Hi Graeme, 

The earlier Wayfarers like mine have combined air buoyancy and storage tanks fore and aft for storage of luggage.

My Mk2 has a large removable lid on top for easier access to the aft inside.

It is sealed against ingress of water by a built up lip at the edge of the opening, outside of which is a thick and wide self adhesive closed cell rubber strip stuck to the deck onto which the lid sits, the lid being held closed at the front by 3 over centre clips and at the rear by 3 sliding brackets which push downward as they are tightened.

There is a check which can be carried out by blowing air into the tank and using a pipe full of water to check if the tank is leaking.

I did a check on mine after a few years of not, and found very little leakage. So large hatches can be sealed quite well against water ingress and as you said, if the tank is also full of light stuff, it is harder for the water to get in.

Hope that is of some use.

Dave D.

Graeme: Your recent tests of stability of these 8-foot tenders surely speak for having buoyancy in the sides.

However, on Buddy I would not go as far as making the cockpit seats as closed tanks. I need them for storing stuff, for instance the bulky cockpit cover with its arced battens. As long as the seats prevent large amounts of water from entering in an 60° knock-down, I am happy enough. The combination of some fixed ballast and the high-sitting volume of the boat should help us self-right. Note how the 5-plank vessel will have its lifting volume much higher up when sitting on its side: If the Halibut model had been decked over, it would have had quite a bit righting moment left at 90° heel.
Such knock-downs are not to happen frequently with the intended inshore use of Buddy. The inconvenience of having to bail out some water, is a fine reminder: Memento mori.

The seat fronts of the cockpit will not be watertight, but they will be ‘slosh-tight’, so free water will not slosh from side to side. It would be easy to make hinge-up seat fronts, to turn the seats into two comfortable berths.

The internal part of the ballast is meant to sit a little forward, so that the boat will trim right with one person on board, sitting at the helm.

I am not sure which came first of Halibut or Buddy. My first study of the 5-plank pram was actually the 6m lightweight keelboat, shown below. It taught me how to find the volume, and with the use of constant deadrise, I could even develop the planks, even if my QCAD program is not meant for designing boats.

Arne

PS: Although this discussion could well have continued on the ‘junket boat’ thread, I felt that this quite big matter deserved its own space.

(Check Arne's sketches, section 5-31)

Buddy, an ongoing study  -  now 4.46m long

I miss my Oslojolle, Broremann  -  and I don’t.
(Btw. Broremann is a he from now on. It is a pet name used on little-brothers)

After Broremann received a JR, he became a lovely, stress-free boat to be in. I sailed it as a keelboat, sitting on its floorboard. By letting him heel over a bit, there was much less spray flying. The 50kg iron cb. could be felt. Still, with the low freeboard and open cockpit, one could easily end up in trouble. In addition, the centreboard trunk came in the way, so it was a little anti social  -  definitely not party-friendly.

The Buddy design study below is an attempt to retain Broremann’s good sides, while avoiding its weak ones.

I imagine Buddy to end up with a dry weight between 150-180kg, of which 30-60kg will be ballast. 30kg of the ballast will be in the tip of the centreboard. There are  two watertight bulkheads and access hatches in the deck for those combined store- and flotation-rooms. The backrests behind the cockpit benches close the gap up to the cockpit coaming, so in case of an 80° knockdown, the water will not fill the boat. As the boat falls back upright, some 50-100 l of the water on the bench will fall into the boat and must be bailed out.

(I once built this system into a 26ft keelboat, after it almost sailed itself under, and it worked splendidly well.)

To avoid filling this open boat with rain between my outings, a quick-fit cover with sewn-on, arced ribs would be fitted. Such a cover was a big success on Broremann.
Buddy should work very well with 1-3 persons, and maybe take 4 or 5 on a light-wind evening spin.

Design-wise, Buddy is basically drawn like a shuttle ferry, with circular curves, just as was that 8’ Halibut tender. I have stretched the bow a little, recently to get that bow transom well out of the water.

Have a look.

Arne

Arne

I offer my Webb 14 design for consideration.

The prototype I built and sailed when I was in California proved fast, well balanced, easy to rig and was also very easy and fast to row.

The balanced lusail rig as shown performed well, but could easily be replaced by a double Halibut rig or two of the four panel junk sails shown in my competition dinghy entries.

David.