Arrangement for trailerable powerboat ?

[FAST FRED]

Isnt that gonna limit the highth over all to something like 6'?

WHY?

See Tad's fine example on his site of a nice cruiser with a folding deck house.

The limit would either be a bit under 9 ft to fit in a container or the hight on a trailer under 13.5 ft (in USA).

We have contemplated such a vessel for a long time , and the chance of a rolly harbor with swells from 2 directions would be handled by slipping a pole ( like a 4 inch spinnaker pole) into a socket that goes through the hull from side to side , and then attaching a dink (with similar heavy mounts) on the pole.

As a half ass'd catamaran she should be quiet enough for proper living aboard or sleeping.

FF

[marshmat]

The 8.5m trailer cruiser I'm playing around with right now (computer simulations and tow model, no actual boat yet) is about 7'3" wide and the top of the wheelhouse is about seven feet above the water. Calculations done so far indicate that its stability is just fine. Many of the powerboats in the local marina are sufficiently stable with a 17' high flybridge on a 10-12' beam (although those are utter crap when out on the water). The rolling can be alleviated by going with a fairly stiff hull form and keeping weight low. I see no reason why this boat couldn't have full standing headroom and great visibility with a 39' length and 7'6" beam. Yes, a long skinny boat will roll more than a long fat boat. But when we compare stability, comfort, speed, efficiency, etc. of boats with comparable displacement (and thus comparable cost), the long and skinny ones tend to come out ahead.... they suck on dock fees though, hence the appeal of trailerable.

[thudpucker]

The long skinny boats are more economical to run. No doubt about that. I've been on some of those long skinny buggers in a cross sea. It's a thrill at first and then its a chore.
Make your steering easy so you can make those quick changes at the top of the waves and the bottoms.

I will say that I've never been on a long skinny boat that turned over. Close, but I really dont think we were ever in danger.
If you load up the top of the bridge you might be in trouble. That's the kind of thing I was referring to when I said long skinny boats roll too much.

In Cook inlet AK, the old beach set net boats were long skinny fishing boats that can be beached, because they have the big Skeg.

They are 'muthabear' to get across the inlet in those quartering waves. That Skeg takes over and makes it almost impossible to turn the boat in a hurry.
You wind up getting slammed, and then dropped into a trough, with each wave. Lordy you get tired and short tempered on a ride like that.
But you guys are right, I never felt like we might roll.

[FAST FRED]

Make your steering easy so you can make those quick changes at the top of the waves and the bottoms.

Our plan is a vertical tiller in the pilot house as used on many lobster boats and YC launches. Modern line and large pulleys would keep weight and loads down.

Very rapid rudder movements are easy , but the added + is that a low cost tiller auto pilot should work just fine.

Guess I'm just cheap, as well as lazy.

FF

[fishingaz]

hi kcfc.i own something of the type of boat you are looking for so maybe a search of the arvor range might help you .we own an arvor20 designed for the north sea .so its great for me down here in australia.it is 20 ft
powered by a 85hp nanni diesel shaft drive semi displacement and has a tunnel type of hull aft of midships.and a keel center of that tunnel.and a fine entry at the bow
it is the best type of boat i have ever had but maybe just purpose built like for us .its a fishing boat and troll all day without breaking the bank.it only has a small wheelhouse good enough for three in a blow shut the door and hatches and feels very safe and dry.2 small bunks but not for family weekends.so if this helps you with ideas im glad.sorry i cant send link .i dont know how.so good luck.gary.www.arvor.com.au.

[fishingaz]

oh and it does 20knots at 2800 with clean hull ours is antifould and we get 18 knots

[tom28571]

To accommodate all of your comfort requirements dictates a fairly heavy boat. Parker's commuter, which is a lightweight planing hull is not suitable at all. You need to look at Sam Devlins designs in this size range to get an idea of what is necessary in a boat to provide all you want. Not meant to actually use one of them but to get an idea of how a good designer approaches this set of problems. Look at his displacements and power requirements although most are meant for higher speed.

A shower means something to store all the water needed, a means to heat it, a power water system and some means to store the grey water from it. Microwaves and fridges need their power sources. Four people for a week need a considerable blackwater holding tank too. I expect you know all that but have you figured out how to fit them in any of the designs you considered? Before looking at a design, try to compile the list of requirements and see how much room and what kind of displacement you need. I don't see much headroom on any of the models you show. Easy to get cabin fever, especially with kids for a week.

While you appear to be convinced on the engine in the cabin arrangement, look at what it does to the interior room. In summer, it means a lot of heat too. There are some pretty good IO diesel packages that consume a lot less room and allow much better steering and handling, plus the ability to run much shallower if need be.

I don't remember any shipping container requirements.

[FAST FRED]

I don't remember any shipping container requirements.

The "oversize" which still is very common and ships cheaply

The boat can be

7ft 6 inches wide 39ft long and just under 9 ft high.

Longer costs almost nothing to build in a skinny boat, since there is so little of it.

Flat bottom to stand inside , and load with simple pipe rollers should be considered.

FF

FF

[Bushy]

The Arvor seems like its very good fishing boat, and would suit my needs perfectly. Does anyone know of build kit or plans for something similar

Any help would be much appreciated.

Cheers