Mental yoga

Perusing Duckworks Magazine and the Watertribe videos and pictures, I essayed to draw what I might be interested in using should I ever be able to participate. I have previously done a few drawings to this effect but they were more pointed towards the T200. Being as I finally took a day off after 3 months of work...I felt I deserved the time to play at boat drawing. Here is what I came up with for the following criteria:
Ability to actually get to the race: (it comes in at 18.6 ft x 5.2 ft)...so it is trailerable.
Multichine Stitch and glue: it is relatively lightweight with built in stiffening at the chines, can be built by just about anyone. GM over 5 ft for stability under a decent amount of sail. Enclosed storage for supplies and an open cockpit area for sleeping under a cockpit tent. Relatively decent rowing ability for no wind situations. Good performance under optimal conditions but fairly forgiving under other than optimal conditions. Shallow enough draft to skim over coral, sand bars and other shallows with LR up.

What I actually came up with draws 6" at 860 lbs all up and should come in at around 450 lbs or less. Use of Bilge daggerboards of 75-90 lbs each to open up the cockpit area but provide LR and additional ballast on the windward side when that boat is heeled. The boards are housed in the side decks so they don't intrude more than a couple of inches into the cockpit. It will use a kick up rudder for shallow water. Rig is a Sliding Gunter fractional sloop with the possibility of a Yawl mizzen added if conditions warrant. This should provide sufficient sail area for light air and the ability to go under obstacles when necessary. My apologies if this is bigger than your monitor...I use 28"ers and reducing the size reduces the fidelity of the pics too much.

 

Looks like it be a nice raid boat!

 

Good looking boat. I question it as an appropriate boat for mad cap events such as the Everglades Challenge. One; Way too heavy. Why in the name of Jupiter would you use 75 to 90 pound boards? Move the decimal place to the left about one step and then it will make sense. Objection two: it draws too much water. Six inches is about twice as much as some of the water you might try to traverse.

If I was 40 years younger I would just have to try the Challenge. My boat would not be as pretty as yours but it would get over the mud flats and shallows a whole lot easier. It would have a flat bottom for starters. Maybe lee boards rather than center board or bilge board, and have every effort to keep it as light as possible consistant with a reasonable expectation of survival. The boat would have provisions for rowing as well as sculling.

You do have a really nifty boat here, it would be a credit to anyones boat dock or trailer. But if you are going to do nutty stuff like the Everglades Challenge then go back to the drawing board. For events such as the Texas coast deal you need not change much at all.

 

Actually I expect the boat and rig would come in at less...I kinda over estimated the weight but it was off the top of my head. I suggested heavy boards for some ballast to counter a reasonably large sail...this also was off the top of my head...perhaps 1 or 2 too many beers skewed my thought processes a tad. I also hadn't considered doing the front deck area as SOF to lighten things up a bit until I looked at the design again...although 3 mm Okoume wouldn't add all that much extra.

The best I can come up with is 3.3" of draft at 700 lbs all up in an 18.2 ft by 64" beam flat bottomed skiff based on the original multichine hulll above. To get 2 200 pounders and 100 lbs of gear and chow and water and sundries...you get a whopping 200 lbs for the boat, rig and fittings...I don't think that 3" draft is a reasonable target. go for 4.5" of draft and we are talking a whole 'nother story...over 1050lbs of displacement at that draft. Two hefty Americans with enough sustenance to keep them from fainting and a bit of extra in case.



PS: I origami-ed the front bottom for a bit of a vee to help with pounding and waterflow. Using a cloth or SOF foredeck and some lightweight 3mm on the afterdeck will help with weight but I would still look for about 250-275 lbs...perhaps even a smidgen more.

If you really want to get 3" of draft...time to get out and walk and pull the boat after you...I don't see any other way of moving the thing in that thin of water. You couldn't row it, you won't sail it in any planned direction because you won't be able to get any kind of board down and you won't have a rudder to help. Even weight shift won't do much as you can't heel the boat enough to steer it properly. Polling it might work but you would probably go faster just getting out and towing it...or avoiding the area all together and sticking to a bit deeper water. I still think that 6" of draft could make the trip. The original drawing would only draw about 4.5" without passengers and would probably tow easier whilst strolling among the starfish so I won't throw it out just yet.

 

The original boat was a lot prettier, but we probably cant have everything except in our dreams. The flat bottom will bring with it some structural considerations that were less demanding on the first one with the segmented bottom.

Correct me if I am wrong here. If you have twin heavy bilgeboards, won't they tend to counterbalance one another and fail to create the RM that a centrally located heavy board might? Looks to me like you have enough chine beam to have plenty of stability without ballast. That is unless you get too generous with mast height and sail area. For me, too much sail is a bummer. I'd rather have a modest amount of sail that was easy to deal with and easily dousable and stowable. I'll accept a bit less performance for the trade off of simplicity. At least in the case of long term or arduous trips where fatigue is a factor.

My first thought was that you might be thinking of events such as the Everglades Challenge. Of course there are plenty of other events that have more sanity. I have pottered around among the areas that the challenge would take you. Sailing is possible for most of the way but there are some areas where the going varies from difficult to absurd. Part of the course is in Florida Bay. A notoriously shallow patch of water that is a long way across. Shallow as in from 12 to 48 inches at low water. The tides there are almost ignorable so that is not a serious design consideration. The mud flats, saw grass, poisonous plants, and voracious blood sucking insects are the main misery factors. Well there are a few sharks swimming around too. There are few, if any, aids to navigation in Florida Bay except on the far east side where the ICW is located. So you have ample opportunity to get lost, go aground, or wonder why in hell anyone would do this sort of thing.( I'd do it without hesitation if my body and skills were up to it.)

 

My (plastic) kayak draws 4-1/2" and has 2 grooves in the bottom which, I assume, act as keels or stiffen the bottom. The local pond has several acres that can be covered in a few inches of water, over Gord-alone knows how much black, slimy mud. Impossible to judge the depth on any one day and varies a couple of inches from day to day, from "I can get through" to Oops.

The kayak will run smoothly into the mud without warning, slow to a gentle stop, and then it's a hell of a job to get it back to real water again by poling. No sharks but I really don't fancy getting out to push there!

My home-designed and built canoe is a 5-planker (narrow flat bottom and garboards), draws a hair less and has a fairly deep skeg. If I run it into the bad stuff the skeg drags in the mud and gives me a heads'up. I just slide the seat forward to raise the stern and paddle out again.