“The fragile horse-powered ferry in Burlington Bay is the only archaeologically studied example of a turntable “team-boat,” a once common North American vessel type. Animal powered vessels were introduced into North America in 1814. They became a popular form of transportation for short-distance river and lake crossings, until the middle of the 19th century, when they were surpassed by the increasing use of steam power.
Lake Champlain’s long, narrow shape created the need for many ferry crossings between Vermont and New York, crossings that were ideally suited to horse ferries. The use of horse ferries on the Lake appears to have peaked in the 1830s and 1840s”
Source: LCMM ( https://www.lcmm.org/…/vermont-underwater…/horse-ferry/ )
On today’s episode of “Is this a shore dive?” Our target was the wreck of the Burlington Bay Horse Ferry in Lake Champlain. Although it’s usually reserved as a boat dive the Horse Ferry is probably the easiest and most beginner friendly wreck that is commonly dove in Lake Champlain. The wreck sits in approximately 45-50ft of water off North Beach in Burlington, VT and is north of the Burlington breakwater.
Last year Heather, Dave, Scott and I dove the General Butler from the Burlington Breakwater launching from Perkins Pier. This was the first in the series of “Is this a shore dive?” Finally few weeks ago John and I successfully linked the OJ Walker from the southern water intake pipe coming from Burlington Water Works Park. This makes the Burlington Bay Horse Ferry the next logical wreck to dive from shore. Me and Tom previously did an exploration dive last year following the most southern pipe to the end of the intake so we had solid GPS data and dive planning metrics from that dive.
This would make 3 wrecks in the Lake Champlain Underwater Historic Preserve that are easily DPV (scooter) accessible from downtown Burlington, Vermont. I say “easily” with some caveats and warnings. These dives although shallow are very much a virtual overhead environment in the summer due to high boat traffic. I would only recommend doing these in the early spring or fall/winter when boat traffic is minimal. Our average depth for these dives for planning is around 35-40ft.
They’re also considerable distance from shore. You should plan to have enough gas reserves to swim back in the event of a scooter failure (a long fucking swim) and/or a scooter with enough burn time to tow a buddy. The alternative is to tow a backup scooter. I already went over scooter burn time in a previous post so I won’t get too much into it.
I’m sure people reading this post know that most “expedition grade” technical scooters like the Seacraft, Suex, Bonex, etc have no issues doing dives in these ranges. You really need to plan these dives carefully on the Blacktip since the battery reserves are much smaller.
Blacktip Batteries
The Blacktips with 2xDeWalt 12Ah batteries are rated at 3.5 miles or 123 minutes of runtime. This is also based on a single tank diver in low drag configuration (Tahoe Benchmark standard). This is factoring in drysuit + doubles + AL80 stage + towing a flag. We are very much running up to the edge of the rated burntime of these scooters for the dive to Horse Ferry. In cave or real overhead environment you should not be diving anywhere close to the limits of these burntimes. We gave ourselves a slight pass since this is really open water diving with no decompression. We also limited our cruising speed to no more than speed 3 or 4 which is quite slow on a Blacktip. Running at high speeds would quickly burn through battery reserves.
For these dives we used doubles and a stage bottle. Like our previous dives we breathed the stage bottle first preserving backgas. I didn’t keep good numbers for this particular dive but I ended up with 2100psi in my LP85 doubles and 900psi in my AL80 stage bottle. I never actually hit turn pressure in my doubles. We went pretty slow on the way back looking for bottles and stopping along the way and could have definitely picked up the pace a little bit.
Custom 20Ah Battery
While I mentioned 12Ah batteries above I was actually testing a custom 20Ah pack that I had an eBike battery builder make using Samsung 50G 21700 5000mAh cells. This effectively gives my Blacktip an estimated range of 5.8 miles with 205 minutes of burntime at cruising speed. Quite a nice step up from the 12Ah batteries. The pack is 10S4P (40 21700 cells). This is 720 watt-hours (36V x 20ah) compared to the 2xDewalt 12Ah which are 216 watt hours each (432 watt-hours total).
This was my 4th dive using the 20ah battery. I ended the dive with approximately 51% capacity left. I’m still tweaking the weight and trim of the scooter but I’m 90% there. I still need to move the weight of the battery a little more forward so that the scooter trims out perfectly but I’m guessing close.
Now back to the wreck of Burlington Horse Ferry. It’s actually a pretty boring wreck but it has a very interesting history and is quite unique archaeologically speaking.
Based on sidescan data we knew the horse ferry passed very close to the northern water intake pipe that runs approximately 1.5 miles from shore. The intake pipe served as sort of “primary guideline” to help us location the wreck.
There was some discrepancy about whether the Horse Ferry was on the southern side or northern side of the intake pipe. The NOAA nautical chart is not completely representative or accurate. If you plot the GPS coordinates of the horse ferry it looks like it’s northern side of the pipe but that’s only because the location of the intake pipe is not accurate on the chart. The intake pipe is a bit more north as you can see from the GPS track line. The wreck itself is on the “southern” side of the water intake pipe approximately 75-100ft away.
Unlike the OJ Walker dive we really didn’t have to navigate to the wreck or figure out a proper course heading. The 3 of us simply scootered adjacent to each other on the left side of the pipe approximately ~25ft apart. John was the scootering on the outside (furthest left) and was the first to spot the wreck.
We scootered around the wreck a couple times (more than enough really) and then continued onward to the end of the water intake pipe which is approximately ~1500ft past the wreck of the Horse Ferry. At this point the battery reserves on the 12Ah Blacktips were getting a little too low for comfort so we turned the dive.
Total Distance
Our total distance navigated underwater was 2.8 nm (3.2 miles roundtrip). No scooters were harmed in the process and nobody had to swim or be towed back to shore. As with our previous dives I towed my GPS-equipped dive float so I was able to capture our track line and GPS data.
