Canoe outrigger project

[2airishuman]

I am having trouble with stowage and may have to shorten it by a foot or so for the next iteration, or change the shape so it will fit under the thwarts, yoke, and seats. I haven't tried everything so there may still be a trick to working it in there.

A photo of spar varnish application...

 

[2airishuman]

The tradeoff, of course, is that the longer it is the more stability can be gained for a float of given displacement.

My design goal was to support a 250 pound diver climbing into the canoe while as close to it as practicable. Due to the tumblehome shape of the canoe hull the center of floatation for the canoe in this situation will be slightly toward the diver from center, but there will still be approximately 30" laterally between the divers' center of mass and the canoe's center of floatation. The arms are long enough that there's about 40" laterally between the diver's center of mass and the float's center of flotation. 3/(3+4) of the divers weight will therefore be carried by the float, or 107 pounds. That's close to the design net displacement of the float (net of its own weight), although I think as-built I ended up with slightly more displacement than I designed in. The point of all this is that I don't think I can shorten the arms without using a bigger float. Some field testing will be required to find out for sure, because the amount of stability required and the exact lateral distances are difficult to estimate.

 

[fjpatrum]

I think (though I'm not certain) that if you arc the amas over the boat, instead of keeping them level, you'll get a better downward force on the opposite gun'l and increase your displacement somewhat.

Alternately, you could rig your sling to pull down on that side of the boat as you step into the stirrup on the other side. (think slinging under the boat into both cross-piece anchor points with the stirrup then hanging down on the float side.)

Both of these options may help you shorten the amas a bit though, like you said, it would probably take some field testing to verify.

 

[2airishuman]

Loaded up and ready to launch. There was a 15 knot offshore wind. I wanted to dive a little reef on the other side of a nearby island but with the stiff wind and me paddling alone I decided to just anchor by the island and call it good. I paddled from just fore of the yoke with my knees on the black towel.

I don't have a very good underwater camera and the wind and chop made photography difficult. This is the outrigger and float.

Here's a shot from the surface as I started my dive. You can see the chop and the taught yellow anchor line.

Not a very good photo, viz was five feet at best, but this is the reboarding stirrup, suspended about 8" below the bottom of the boat. To get back aboard, weight belt comes off and is placed in the boat first. I take my kit off in the water and tie it off to a line so I can haul it in after I'm aboard. Then I put one foot in the stirrup, one hand on the outrigger, other hand on the gunwale. It takes some modest athleticism but it's enough to get back in.

 

[kevindsingleton]

Looks like a great setup. Thanks for the pics!

 

[John C. Ratliff]

Very good! I have an 18 foot Wenonah Sundowner that I have used on rivers. Usually I have taken my diving equipment in it and gone to shore to do the dive (I've only done this a few times). But I'm following what you are doing and may do it myself. I have also thought of simply towing my Dacor Nautilus CVS scuba behind the canoe, anchoring and getting into the unit in the water.

These canoes will handle more gear than a kayak, and are very stable in rivers too. I handle my fiberglass Sundowner myself, and can carry it to my car, or to the water, easily. Kayaks would be harder to handle. Here's a photo of me on my Sundowner. and also my kids using it when they were young. This canoe was bought in the 1980s, and is still going strong.

 

[2airishuman]

Nice photos, John. The 18' Sundowner and my 17 Wenonah are more alike than different although canoe enthusiasts will debate their relative merits.

Very good! I have an 18 foot Wenonah Sundowner that I have used on rivers. Usually I have taken my diving equipment in it and gone to shore to do the dive (I've only done this a few times). But I'm following what you are doing and may do it myself. I have also thought of simply towing my Dacor Nautilus CVS scuba behind the canoe, anchoring and getting into the unit in the water.

I gear up in the water also.

There's a lot to be said for using the canoe for transport and diving from shore. In Minnesota there are fairly expansive (compared to neighboring states) state laws on public water access that grant public access up to the ordinary high water level, so except for really steep banks it should in theory be possible to dive along the shore and leave the boat. That said the landowners, especially in more built up areas, don't take kindly to that sort of thing, and there are some steep banks.

 

[John C. Ratliff]

For those of you who prefer kayaks, we used to have boats made specifically for diving and spearfishing. Shown here is a paddleboard I used in the 1960s for free diving for fish. It could hold a single steel 72 tank in the center section too. But apparently, those are no longer available.

I really like my Wenonah canoe, and don't plan to give it up for a kayak anytime soon. Rather than that, if I get into really wild water, I'll simply buy the floatation bags for them. I really like the idea of outriggers for this canoe too. So maybe this is my winter project.

As you can see, I solo paddle this canoe with a double-bladed paddle in current. I can go upstream is small rapids with this technique. I always kneel when doing this, as it is much more stable, and provides more control of the canoe. Wenonah now makes a thigh strap system that gives even better control of the canoe when kneeling. The paddle I use is made from two different kayak paddles. The center section is for a longer paddle, and then I put two kayak paddles on it so that I can paddle from the center-rear section of the canoe, using the rear thwart as my "seat." It works extremely well.

I remember one trip where we rented a Gruman canoe and took our dive gear to the opposite side of Blue Lake in the Oregon Cascades. I did an experiment to see whether using a space blanket would provide any more protection from cold than the underwear inside a dry suit (it doesn't). The dive was very interesting, as we entered the caldera of the lake from the southwest side, and onto a vertical drop-off. We It was a great dive in a wonderful setting, made possible by the use of the canoe. Here's part of my dive log entry:

Dive Plan: The plan was to dive to ~75'. Time was unspecified. We carried tables (both altitude and "no-calculation") plus twin tanks. Carried a marked line to show depth.

Observations:
Get into the water w/ the full-face mask (w/had a protective neoprene around the skirt) mounted on my Trieste II double hose regulator (reg. w/ octopus, power inflate & submersible gauge) in place and it felt like I was still in air, except that I was weightless. It was really nice to have no cold shock whatsoever. Descended to ~30' & found I was heavy, & so took off two pounds from weight belt. Bruce wanted a pre-dive briefing & so we surfaced and decided no a 75' max depth & 30". (This works out to 100' for 50"). I got to 75' & looked up to see Bruce at ~40' signaling me to come up. Tom was daving trouble getting down. At this point Bruce & I decided on a 40' max for this dive. Even at 75' I could barely make out some large boulders w/ were at ~120 ' which may have been bottom. We worked the cliffside on the dives, finding very interesting fissures and ledges. Al/so saw a forked tree top (tree must have been ~200' long at ~2[' from horizontal angle). Another interesting sight were the pale-green underwater moss that we saw at the 20-40 foot level. Took a lot of pictures of this & it should be interesting. Cut the dive at 60" to undergo decompression. During decompression we (Bruce and I, Tom had surfaced --40' for 50") created an underwater slide of large proportions. It began small but grew until it was a large cloud as it rolled over the cliff side at ~40 feet. It started in a large fissure at ~15 feet. Also saw a school of whitefish at 10' when on decom. Hopefully got a couple of pictures.

This dive occurred on May 25, 1975. Since we were planning to dive to 75 feet, on our decompression tables that was an 80 foot dive. We were at 3500 feet of altitude, which with the altitude correction factor I was using at the time made it a 92 foot dive, so we said we were diving to 100 feet on the schedule. I have an area of my dive log which is for listing "Special Problems and Ideas." Here's what this one said:

Special Problems and Ideas

1. Dive planning poor. 2. Aborted deep dive at correct time. 3. Took prescribed decompression for almost a full dive at 75' (safety +). 4. Suit leaked badly, but I wasn't terribly cold--Bruce was colder in leaky Unisuit. 5. Space blanket material doesn't work. Heat lass apparently by conduction and convection rather than radiation.

The marked line was because we recognized that our depth gauges would not tell us true depth, and we didn't want to use a calculation while in the water.

SeaRat

 

[The Kraken]

PVC !!! I did the same thing. See if I can get some pics.
Got a piece of expanded aluminum sheeting to make a gear platform and zip tied it to the PVC tubing..

Safe dives . . . . . .
. . . safer ascents!

the K