Hydroelectric Plant Sluice Gates: 2018

Whoa! The extraordinary river flow of 2017 caused some pretty drastic long-term changes to the HydroElectric Plant route.

Perhaps the most obvious is the change in the sluice gates.

This is what they used to look like:HE-Plant-Sluice-Gates---My-Sketch labelled-web

But this is what they look like today! It appears I need to resketch my sketch!09-HE-Plant-boards-gone-2018

The boards have been blown off and are now lying here and there around the gates, some in front, some inside the headpond. They went every-which-way from the constant eddies in front of and beyond the gates.

So… now you have to pay attention to the debris in front of each gate to know where you’re at, since the gates themselves all look identical. My photos aren’t the best at the moment because the visibility was bad the day I had a close look. But they’ll give you an idea.

Gate 1 (closest to shore):

Here’s what it looked like in 2016: 5 boards in place above the concrete sill.

Here’s what it looks like today:

The 5 boards are gone. Weeds cake the posts but they remain solidly in place. (Note the indentations in the canal wall. They were for “stop logs” – beams which were slid into them to slow or stop water flow if repairs were required on the gates themselves.)

The gate height is (obviously) lower and the hill of silt in front is higher so that as you approach, the current threatens to carry you over the gate before you’re ready. Be wary.

Gate 2 (middle):

Here’s what it looked like in 2016: bottom and top board in place. This photo was actually taken from inside the headpond – looking back towards the gate.

sluice-gate middle-from-headpond-web

Here’s what it looks like today: HE-Plant-second-gate-2018-web

No boards. And no weeds – hmmm.

Gate 3 (furthest from shore):

In 2016, there were no boards on top… just like today!

The debris in front of each gate differs. I’ll work on getting some shots of each and pass it along to you!

 

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Tanker “Chem Norma” Aground on Lock 23

Quite the start to the 2018 dive season!

Larry and I were awakened in the wee hours of a recent clear night by the sound of a long, loud foghorn, followed by the frantic grinding of an engine in reverse. We looked out into the night but could see nothing amiss.

In the morning the cause was clear when we walked over to the public dock. The Chem Norma was sitting there at a slight list. We believed that it had run into the berm of the southern wall of Lock 23 which sits about 13-15 feet below the surface. You can see the yellow buoy beyond the rear of the ship, designating the eastern end of the lock below.

Chem-Norma-Aground-May-29
view from the public boat dock

We learned that the double-hulled tanker (all tankers travelling the St. Lawrence Seaway are double-hulled for safety) had lost its steering and drove into the channel wall, but that it had suffered no damage.  Efforts would soon be underway to set it free.

This proved tough. Over 4 days, up to three tugboats worked to pull the ship off without success. Ultimately shifting the cargo to one side and getting the International Joint Commission – St. Lawrence River Board to temporarily raise the river by a foot (by reducing flow through the downriver dam) freed the boat.

Chem-Norma-and-Tugs-web
overhead view using our drone

Yesterday a few of our senior divers drifted through the area on the southern side of the southern lock wall. Although there was no obvious wall or berm “wound”, there was gravel and larger rocks strewn everywhere, old lock bollards were surrounded by rocky debris, and the divers found what was probably one of the ship’s sacrificial anodes (hahaha, as if I know anything about sacrificial anodes… but my divers had heard of them and a quick Google search taught me a lot!).

Chem Norma Anode
anode

Here’s what they found. If you come across it, kindly leave it there!

We’ll be out again soon to evaluate this area further.

In the meantime,  now that all the sludge and mess from the working tugboats has cleared, river conditions are pretty typical for this time of year – moderate current, 10-foot visibility, 13C/57F water temp.

 

 

Dive Conditions Update

Along with anyone living in southern Ontario and Quebec this spring, we’ve been watching carefully the weather reports and specifically rainfall statistics… and we’ve been driving up and down the shorelines to inspect areas we know. There has been flooding and damage to many, many riverside properties.

Lake Ontario levels remain higher than at any time in the last century and the International Lake Ontario-St. Lawrence River Board is carefully releasing the extra volume at as safe a rate as possible – to reduce water levels along affected shorelines while still protecting Montreal from flooding.  They expect it to take several weeks. We’ve learned a lot about the strain this has put on international shipping: freighters have difficulty maneuvering upstream against the dramatically increased current and are in constant contact with authorities regarding conditions.

Morrisburg itself is protected from extreme water level changes by the dams 12 km upstream at Iroquois and 40 km downstream at Cornwall.  Therefore the water level at the Lock 23 site is virtually unaffected. It’s the current that has dramatically changed dive conditions, and ongoing rainy days are causing an accumulation of additional sediment.

Current Conditions:

  • FAST CURRENT on the approach drift in the canal. Normally it takes about 15-17 minutes to drift from the entry point to the lock gates. Yesterday it was fairly normal in the centre but much, much swifter at the edges – it took a mere 7 minutes on the inside drift to the Hydroelectric Plant sluice gates.
  • EXTREME CURRENT at the gates. Normally divers can stop at the gates and check on buddies, etc., before going up and over whatever wall they’ve arrived at. At present it is extremely difficult to do so – divers are easily swept up and over the gates by the current.
  • MODERATE CURRENT on the exit swim. Normally there is no current at the end of the locks and on the way out – divers set their compasses to NNE to consistently exit at the beach. We are currently swimming at a NW (and occasionally almost W) setting to reach our planned exit point.
  • EXTREME BACK-EDDIES and whirlpools in the locks themselves. It is difficult even on the river bottom to move against them – feeling suddenly like you’re battling that current upriver. It settles as you move downstream but it can be very fatiguing.
  • SILT HILLS where you don’t expect them… like on the wrong sides of gates! Likely this is due to back-eddies.
  • POOR VISIBILITY. Sediment and stirred up waters has reduced visibility on occasion to 5-8 feet.

On the bright side… it’s early in the season and there are ALMOST NO WEEDS!!

All of this provides a new environment for divers – it can be a tremendous amount of fun if (1) you are experienced with currents, (2) you are comfortable working with the currents and eddies, letting them on occasion carry you over and beyond a difficult spot, (3) you know the landmarks and layout of this dive site and can proceed from where the current has set you down, and (4) you have excellent air management even with increased physical demands.

At this time, therefore, it should be considered an appropriate dive site for experienced, advanced divers only who have excellent air management, good lights, a compass and a surface marker buoy for use on the exit swim (DON’T try using it in the locks!).

Good diving to you!

Feel free to email me if you have any questions!

Sydney

sydneyschnurr@gmail.com

 

 

Leaving the Locks: the Wharf and Ferry Dock

When you reach the final cribbing of the tailrace described in this post, by whichever way you got there, you now have the opportunity to explore the municipal wharf footings and the ferry dock and road on your way back to shore.Full-Lock-Wharf-and-Ferry-Dock-with-ArrowsYou can leave the locks from anywhere you wish, but the photo below shows the relative distances from shore. Anywhere you see land in the photo, you’ll swim through weeds today. (Should you decide to leave from the locks themselves, therefore, your entire long swim in would be weedy, and you’d end up far short of the beach.)exit-possibilitiesweb

So… you’ve come to the end of the 3rd cribbing and found a line heading north from the north side of the crib. Do NOT take this line (well, of course you can take it; it will take you towards shore but you won’t see the wharf or the ferry dock – more about this exit in another post to come). Instead, swim around the corner (to the east side of the crib) and continue east from there…22 crib3d line-out-dont take the line webIt’s a matter of striking out over sand with no initial landmarks. Your friends are the tiny patches of weeds in front of you bent flat along the sand in the direction of the easterly current. They’re flat because the current is stronger than it seems. Stay tuned to your compass – you want to go east with the weeds!01-tiny-weeds-east-in-current webIn a minute or two (when you are new to this, it seems forever), you’ll start seeing other landmarks. They change somewhat from the start of the season to the end with their accumulation of weeds, but they are specific to the area. The leaning posts should be on your left. The boulders should be on your right.

Keep your eyes peeled ahead for some well-worn wooden debris, followed by a long wooden beam, usually seen on your right, lying on the sand pointing east.

Attached to the end of this beam is a line – heading north. Follow it!09-beam-end-with-line-webThe line will take you directly to the municipal wharf, a large, well-preserved foundation with smooth, squared, intersecting beams outlining the shape of the wharf. The engineering is interesting, and there are usually lots of fish hanging out here.

You now have 2 choices: First – you can go around to the north side of the wharf and continue following the same line north to reach this big hunk of cement. We don’t know what this is… perhaps a counterweight for shipping or a crane?  It’s shaped like a coffin so it has been dubbed “Jimmy Hoffa’s Grave” (look it up if you don’t know who Jimmy Hoffa was!).

13-jimmy-hoffa-grave1-web 14-jimmy-hoffa-grave2-web

Then, with eyes glued to your compass, head north-east over sand to the ferry dock.

Your second choice is to leave directly from the eastern edge of the wharf and head north-east to the ferry dock.  Either way, it will be about a 3-minute swim (I think… I forgot to accurately time it last year) over sand without many helpful features until you get close, when the usual boulders and hunks of wood can be found.

The construction of the ferry dock is quite different from the wharf. Whole logs have been stacked without squaring them off. There are chunks of iron presumably used for anchoring the columns.

The ferry travelled between Morrisburg and Waddington, NY in the early 1900s.

Now you want to find the ferry road and follow it towards shore. It heads from the footings of the dock in a slight N-NW direction, ever so slightly into the current. It has posts regularly placed on its western edge and we’ve put a line along these posts. In its day the road was gravel and remains so, looking not much different from the land around it except that it is smooth and raised on a boulder base about 15 feet wide. The best landmarks are the posts. Follow them to the end where the line is attached to a larger base. The depth is about 15 feet.

As you near the end of the road, the weeds begin. Head directly north through them and you’ll find your way to the beach, crossing over the old Highway 2 (see photo at the top) along the way.  You’ve still got about a 5 minute swim and it’s pretty shallow – about 8 feet – so deploy a surface marker buoy to alert boat traffic!25-weeds-in-to-beach-web

 

Middle Route: Rapide Plat Lock (1847)

The approach to the locks is described in this post. You want to arrive at either of position #2 or #3 described there.

You’ll pass over a tire (the only one in the entire site) and come upon a pile of bottles at the base of the lock’s upstream gate.

I’m calling it a “gate” but with research and close inspection have discovered that this is likely not the case. It is more likely a weir. Historical records note that a weir was positioned inside the old lock after the lock was no longer in use, at approximately the spot where the upstream gates would have stood. More about this in a separate post to come.

When you arrive at the weir, take a few moments to examine it. Its surface is smooth and its joints are precise; it is not made of wood (all lock gates were wooden) and it has no openings (all gates had openings to control flow). It points like a V into the current.

The next step is to go up and over.  The current will grab you at the top so ascend slowly and maintain your buoyancy. Note the diagonal cuts at the top, then drop over into the lock itself.

Another clue that this is weir and not a gate is that the lower area has been filled with concrete for added structural support. To the right (south) you can look in the opening where the cables were housed to open and close the gate and see the only location in the entire site that has its gear mechanism still in position.

You’re now fully in the Rapide Plat Lock.  Because of the closed weir there is a fairly strong back eddy that you’ll battle a bit as you make your way downstream.  Take your time.  There’s a ton of stuff in here to inspect, including gate crank mechanisms, parts of the old doors, floor planking, a long electrical standard and a wheelbarrow. There’s construction rubble everywhere.  I haven’t categorized these items yet and look forward to a great many entertaining dives here.

Here are a few noteworthy items:

If you come across this wheelbarrow, you know you’re approaching the downstream end of the lock. It’s sitting on the south side of the cribbings mentioned in this postwheelbarrow-web

Keeping along the north wall of the lock, make your way to the individual cribbings. As described in the post, drift to the last crib and choose one of your end-of-the-lock options.

Inner Route: The Hydroelectric Plant – From Plant Foundation to Tailrace

When you reach the foundations of the hydroelectric plant itself, you’ll find bricks: lots of red bricks piled at the bottom of the plant’s concrete wall with a few still partially affixed at its top.

Pay attention to your direction at the top of the wall.  Moving east over it with the current will carry you through the area of the turbine and tailrace. Moving south (to your right) will take you into the downstream area of the Rapide Plat Lock.plant-wall-SE-corner web with directions

When you slip over the wall and descend, you’ll note a 12-foot drop in depth. downstream-side-of-plant-wall

If you move to your left (north), you’ll see a large tree stump on the north embankment. If you move to your right (south), you’ll see the shorter, wider stump on the wall between the plant and lock.  The south stump is considerably larger and therefore a good landmark.

On the northern bank area of the tailrace, there are a lot of small posts and debris to examine. The depth of this northern “shoreline” gradually rises to 12-15 feet and becomes weedy. You don’t want to exit here – you are still a long way from shore.

The dive route itself is to the east, through the tailrace area and a multitude of posts and supports from docks and boathouses. There are back eddies at the beginning but as you move along, the current drops substantially. You can take your time investigating all there is to see here. Below are the tall landmark posts of the tailrace.

To the right (south) of these are three large cribbings distinct from the stonework leading downstream from the plant. These structures supported the dock running eastward. They are the major landmarks that lead you to the end of this route.

Although built with similar dimensions, they’ve been variably affected by the river’s flow. The first has sustained the greatest damage; the third is nearly intact. They are all large and interesting to explore, with large beams along their sides and tops filled with round stones.  Each of them has a series of iron rods protruding from the top beams.

The visibility between the cribbings can be poor so that when you are at one you may not be able to see the next until you get close to it. It is important to know when you’re at the final cribbing because it marks the spot at which you change course toward the exit.

Crib 1: Broken with contents strewn about. The beam with its iron rods, normally found on the top, is lying on the ground. The second crib is barely visible in the distance.

Crib 2: In better shape.

Crib 3: In the best shape. Paying attention to the steel bar positions along the top helps you know which crib you’re at when visibility is reduced.

Follow the 3rd cribbing around its base to its NE corner where you’ll see a line attached and extending northward towards shore.

crib3c-base-webcrib3d line-out-web

This is an important landmark for choosing your route home – following the line is one of your options. More about this in a separate post.

 

Top o’ the Wall: Between the Old and New Locks

02-Lock-23-Close-Up-with-labels-web

In this photo, courtesy of stlawrencepiks.com, you can see the grassy section between the two locks. Starting upstream, note its important features: the initial curved approach wall, the dark rectangular and circular flower beds, the lock house in the centre, the position of the downstream Lock 23 gate, and the drop in depth where the wall curves inward, showing the stairs leading to the lower level and the larger sideways stairs at the end of the grassy area. The second set of “stairs” was merely the staggered face of the sandstone blocks where they changed levels. Remember that the lock provided 12 feet of lift – the drop is simply the difference in water depth between the lower and upper gates. Moving out of the photo in the lower right corner is the long approach pier where ships waited for their turn to enter the locks.

Below is a photo of the same area. Envision yourself standing beside the centre lock house, looking upstream. The flower beds seen as dark spots on the photo above are bursting with flowers in the one below. Notice – on both photos – how much wider the concrete rim is on the new lock (Lock 23) compared with that of the old (Rapide Plat Lock). The bollards (mooring posts) are large on the new lock, small on the old. All of these are landmarks for the diver today.

And here’s a photo of the lock house. The one at Lock 23 is gone but the one at Lock 25 in Iroquois still stands on solid ground, though a bit weathered a century later!

05-lock-house

This central area had no trees, so today it is the only upper portion where you will not see any stumps. (Corollary: if you come across tree stumps, then you’re not in this area of the locks!)

The Dive Today:

You can get to this area by ascending anywhere along the length of either lock. However its very beginning is the curved wall at its upstream end. This is the ONLY fully curved end wall of the entire site so it’s an important landmark. I describe reaching it in this post.

Here’s is what it looked like at the time.0001 old photo

Here is what it looks like from its base today.

rounded-end-1-webIf you ascend here, you’ll notice a couple of distinct features at the top.  First of all, there’s the ripping current that I keep mentioning that is present at the start of all the lock walls. You are a mere 15 feet from the surface so take great caution with your buoyancy to keep from ascending further. Secondly, you should notice the curved concrete rim of this wall, covered in zebra mussels but virtually no plant life. Keep close to your buddy – it’s easy to get separated. The entire drift on the “grassy” portion will be at 15 feet or less.

For a bit of a challenge, head quickly south (to your right) over this open patch to the first big bollard you see. It has a rope attached to it. We call it the skier’s rope –  a remnant of bygone days that’s fun to grab on to and face into the current, maintaining a water-ski stance. It’s trickier than it looks!

01-ski-rope-bollard-web 02-skiing-web

When you’re ready, turn and drift with the current. It will carry you right to the end of the grassy area and your exit point. You can move to your left or your right to view items along the way, noting the large concrete edge on the south side (Lock 23) and the narrow edge on the north side (Rapide Plat Lock).

03-the-wide-rim-web
The wide rim of the new lock
04-the-narrow-rim-web
The narrow rim of the old lock

You’ll pass the Lock 23 upstream gate indentations at the beginning of your drift. The central grassy area is now seen as a base of small boulders and weeds. Early in the season you can see the boulders, later on just the weeds whipping horizontally in the current. There are usually a lot of catfish, walleye and bass up here.

Pass a downed light standard or two, then notice a break in the weeds. Move north (left) to see the remnants of the foundation of the lock house, which tells you that you’re roughly in the centre part of this site.06-foundations 07-foundations

There’s definitely current here!08-weeds-in-current-web

As you skim along, note the indentations in the south wall where the gates were fastened, the holes where the cables ran (the holes are not large enough to swim into), and the gate opening mechanisms. They’re interesting to examine but difficult to do so in the current. There’s also a light pole lying lengthwise just ahead.

09-cable-hole
cable holes
10-cable-anchors-web
crank mechanism supports
11-gate-indentation-web
wall indentations for gates to swing in to
12-light-post
light pole 

When you see the crank mechanisms (refer again to the photo at the beginning of this post), you know you’re at the downstream gate. You’ll come across a few odds and ends of debris, then the end rim of the wall as it curves in, then a drop in depth. Move left to see a slab of concrete beside which stood the original wooden steps. This is the drop to the lower level of the lock, which looked like this…13 lower levelWhen you reach the sideways “stairs” marking the end of the curved wall, you  find yourself on the long concrete covered approach pier at about 25 feet deep. It is marked with bollards 50 feet apart along its length as well as several downed light standards.14-Lock-23-full-with-drop-in-depth-and-approach-pier

You can drift right to its end, then head north towards shore, or leave at any point along the way.

 

 

Inner Route: The Hydroelectric Plant – From Sluice Gates to Plant Foundation

The innermost route (the one closest to shore) takes you through the Hydroelectric Plant built in the late 1800s. Water was directed from the canal into the plant’s headpond, then funneled into the turbine to create electric current for nearby transformers.

Here’s a sketch of Morrisburg’s plant with its inflow “headpond” and its outflow “tailrace” area. I have also shown the 1847 lock alongside it. At the level of the turbine, the water level drops 10-12 feet. So does the grassed area between the plant and the lock, with stairs between the two levels.

HE-Plant-Overview---My-Sketch-with-Landmarks

HE-plant-close-up-web
photo courtesy of stlawrencepiks.com

All of these areas are easily identifiable underwater if you know what to look for. The plant has been demolished and strewn about. The turbine is buried beneath the debris.

If you approach (see this post – it’s #4) by drifting close to the sloping north canal wall (that’s the one closest to the Canadian shore!) at 16-18 feet, you’ll start this section at the vertical wall leading to the gates. The arrow below marks the location.Lock Entrance Overview - My Sketch start of wall rotated 180

The end of the wall looks like a staircase up to the wall itself, which leads to the innermost sluice gate.

The three sluice gates mark the entrance to the headpond and they’ve weathered the years fairly well. With differing top boards missing, each has a distinctive look to let you know where you’re at.HE-Plant-Sluice-Gates---My-Sketch labelled-web

A walkway across large stone supports allowed workers to operate cranks fastened to the metal posts you see today. These opened the sluice gates to control water flow. The cranks are gone but they looked like this.

The cranks in these photos are located at Lock 25 in Iroquois. Much of that lock is still above water and if you wander around it you’ll see many of the mechanisms used in Morrisburg. Note the stone support structures.

Here’s a photo from stlawrencepiks.com showing the walkway and the cranks in Morrisburg. The upper gate of the Rapide Plat Lock is just beyond the walkway. The indentations you see in the support structures were called “drop slots”. Large wooden beams were dropped into them to provide protection from ice floes during the winter.

EPSON scanner image

Here’s what the sluice gates look like to divers today.

When you reach the gates you must go over them to get into the headpond. Use caution at the top as water flow is very strong and you come within 12-15 feet of the surface. The photos have been taken from both sides of the gates.

To get through the headpond, your next decision will be to either swim close to a wall or through the centre, ultimately reaching the funnel area where the turbines were. You’ll notice that the swim is not easy. There are fairly strong back eddies since river flow is obstructed, making it feel like you’re working against the current. Flow normalizes as you move downstream.

The stepped back ends of the support structures are easy to identify. Notice the hills of silt between them on the downstream side of the gates. If you’ve gone over the 3rd gate (southernmost), or swum over to it to approach the south wall, you’ll also see this circular item just inside. It is an important landmark because if you’ve been travelling another route and been “blown off course” it lets you know where you’ve ended up.

Choice 1: Some divers prefer to travel along the top of the north wall and then along its 45-degree angle leading to the plant.

Choice 2: Some divers prefer to swim to the south wall and follow it along the bottom until it angles to the right at the plant.

You can pull yourself along the ground. You’ll feel a bit like you’re going uphill but it’s actually all the plant debris that has been dumped into the headpond, including many bricks and boulders. Ahead of you is a concrete wall.

Power house Lock 23 old photo

The plant’s foundation rests on top of this wall with loads of bricks all around. You know you’ve reached it when you see the concrete in front of you and these capacitors lying on the ground. The photo on the right is a contemporary shot of capacitor locations in overhead wiring. Refer to the first diagram at the start of this post to see where they would have been located on land in Morrisburg.

Plant debris is strewn everywhere, including boulders and bricks on the bottom and bricks all over the walls.

Move on to the next post to see what lies beyond the plant foundations.

 

 

2. You’ve Arrived at the Locks… But Where?

The site is large and, since you’re always drifting, you get to see only a portion of it each time you dive. It’s nice to know which section you’ve arrived at when you reach the stone structures.

Here’s the direction from which you’ve come:Lock-Entrance-Overview---My-Sketch-with-Approach-Direction-web

Here are the primary landmarks when you get there (details below):Lock-Entrance-Overview---My-Sketch-with-Landmarks-web

Here are the 4 most common spots to arrive:Lock-Entrance-Overview---My-Sketch-with-4-Arrivals-web

#2015 08 21 03 Outer Lock Across Upstream Sill to Top of Wall and down to lower level wall across Inner Lock downstream.MP4.Still001

The sill of Lock 23. You reach this because you swam straight south to the farthest canal wall at the start of your dive, then drifted with it on your right side. It becomes the south wall of the lock. The current here is moderate. You only really notice it when you stop at the sill and attempt to cross. Check out this post for details about this route.

#2rubble-pile-in-front-of-curved-wall-web

The pile of rubble and the hill of sediment just before you reach the rounded end of the wall separating the old and the new lock (you can see the wall just ahead). Any time river flow is impeded by a structure, especially a large one, sediment drops and a berm is created. You arrived at this point because you drifted down the centre of the canal. You probably saw a few large boulders and bits of building debris here and there along the way. The current here is strong and it’s sometimes difficult to keep your position if you stop.

The photos below again show the great curved wall that looms in front of you. To reach Lock 23, you need to move to your right. To reach the Rapide Plat Lock, you need to move to your left. If moving left, just before you drift around the corner you’ll see these shaped stones. I don’t know why they’re here (yet); this is the only spot with stones placed in this manner. Check out this post for details about this route.

rounded-end-1-webstones-placed-rounded-end-web

#3second-curve-coming-up-web

The curved section of the south wall of the Rapide Plat Lock. If you continued the drift as explained at #2 (above) and kept the wall to your right, you’ll arrive here. But this may also be the first structure you reach if your drift down the centre was not as far south as you thought. You’ll probably have seen the wall to your right first and noticed that the current has picked up dramatically. As soon as you go to your left around the curve, the current will rush you towards the lock gate.

Just in front of the gate itself, you’ll see this tire sitting in the corner… and a bunch of bottles. This is the only tire on site… but there are bottles everywhere so they’re not particularly useful landmarks. Most of them are fairly recent – the river carries them along and drops them wherever there’s a roadblock.
tire-in-front-of-gate-web bottles-in-front-of-gate-web

Check out this post for details about this route. Note: #2 and #3 are part of the same route.

#405-sluice-gate-top-web

The sluice gates to the headwater pond of the Hydro-Electric Plant. You reached this spot by drifting along the sloping north embankment of the canal (when you entered the water, you did not try to cross the canal, but drifted as soon as you reached the bottom of the embankment, a depth of about 20 feet). The current here is quite mild until it picks up right at the gates where they create an obstruction.

The first landmark noted on this inner route is the stepped end of the wall leading to the sluice gates. It looks like a staircase to your left on the embankment (and you’ll miss it unless you drifted at about 16-18 feet) but it is simply the support blocks at the end of the wall.01-Start-of-Wall-in-to-HE-Plant-a-web

You may also have reached the sluice gates by drifting back towards shore from your drift in the centre. You may have started out at 30 feet but the current tends to pull you towards shore if you are not vigilant at keeping your depth. Check out this post for details about this innermost route.

 

 

 

 

Outer Route: Lock 23 (1905)

The route to the “new” lock is the farthest from shore but also the simplest. It’s therefore the one that most divers take if they’re new to the site. Instructions they’ll have received might be…

“Swim south until you hit the outer stone wall, drift downstream until it runs out, head back north to hit the inner stone wall, drift until it too runs out, then head north.  You should end up at the beach.”

It’s an oversimplification and you’ll miss many of the historical details, but it gets you safely through the site and you’re unlikely to be confused by your location.

Once you’ve entered and found your way to the canal (see this post), continue swimming south until you get to the wall.  You may think you’re swimming too far into the river with no end in sight… but fear not… the wall will show up! It’s easier crossing the current if you move along the bottom. The dark wall looms up in front of you at about 7 minutes.

01-the-wall-web

At a depth of about 40 ft, you’ll coast alongside its massive limestone blocks for another 10 minutes or so until you reach the concrete sill of the lock’s upstream gates (the gates are no longer there). You’ll have lots of companions along the way – bass love to swim with you.

Here’s the sill just ahead.

02-approaching-the-sill-web

You may not have noticed the speed of the current much but you certainly will if you attempt to grip the sill’s edge to steady yourself while you wait for your friends!

You now have 3 options:

1. You can continue drifting along the south wall and over the downstream sill, noting the drop in river depth as you go over it, until you reach the end of the wall. You’ll notice it curve to the right. If you follow this curve (south), you’ll get into the deeper waters of the shipping channel.  Instead, turn north and cross the lock (45 feet wide) to its north wall.

November 2015: at this time I don’t have photos of this yet… they’ll have to wait until next season.

2. You can cross the lock now, using the upstream sill as a guide. It’s easiest to cross at the canal bottom, grasping the sill if you wish (although there isn’t much to grasp…).

03-the-sill-a-web 04-the-sill-b-web

As you come up to the north wall, observe the cables of the gate mechanisms that are recessed in narrow slits in the wall on either side of the sill.

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3. You can cross the lock a little higher in the water without using the sill. The current will carry you downstream a bit as you move across. You’ll probably get to the inner wall about midway down the lock. This lock is 270 feet long so there’s lots of breathing room!

Whichever way you choose, you’ll soon reach the inner wall. You can drift along it at the top, the bottom, or anywhere in between.

06-past-the-sill-to-indent-and-cubby-webIf you drift midwater along the side of the wall, you’ll note the huge limestone blocks, with big angled indentations to allow the gates to close flush with the wall itself. You’ll go past more “cubby holes” (more about these in another post to come) where pulley mechanisms came through to attach to and work the gates.

At the end of the lock, the wall you’re drifting alongside angles inward and changes to wood. This is the approach pier where ships waited for their turn to use the lock. Structural details of the cribbing are interesting and there are a fair number of cold water sponges (I think – though would welcome confirmation or correction) attached to the walls. When you reach the end of the pier, you’ll see its “corrugated” iron wall.  (Sorry, no photos yet of this. Be patient.) At this point there’s nothing downstream but river bottom so it’s time to head north to shore.

You can also ascend to the top of the wall which sits about 12-14 feet below the surface – this is the upper level of the lock and it is described in this post. You’ll be whisked past large bollards (the mushroom-shaped posts that ships moored to) and knocked-over light standards. Originally grassy, the base is now small rocks and weeds bent nearly horizontal by the force of the current. When you reach the end of the lock area, you’ll drop 12 feet to the downstream approach level and be carried along the concrete-covered top of the wooden approach pier. Drop over the corrugated iron edge at its end, collect your buddies, check your compasses, and head north.

You are a long ways from shore – it will be about a 15-minute swim in. Keep north as your compass heading, and stagger yourselves as you cross so that any silt you kick up will not ruin the visibility of those behind you.  The first half of the swim will be at about 35 feet over smooth silt. The second half will be through weeds.  More about these in this post.

The old Highway 2 sits at about 13-15 feet and is a perfect place to complete your safety stop. If you pace yourself “just right” and keep your compass heading “just right”, you will surface at or near the beach. Be vigilant in putting up a surface marker buoy for the last section when you are in shallow waters – there may be lots of boat traffic overhead.