Richard wrote:
On the subject of mono- vs multi-hull unsinkability, I met a couple in an Etap in the Netherlands who told me a story about a couple of lads who opened all the seacocks in their Etap then sailed it around (slowly). Unfortunately, like many sailing stories, it's impossible to verify. I had a good look at their Etap and a lot of the floatation seemed to be quite low down. But this has reminded me to research both the Etap and Sadler designs.
Etaps and Sadler 26 and 29 can be sailed in flooded condition, yachting magazine articles have been written about it, and I think this depends on them devoting much of the volume below berth level to foam between the hull and inner lining. Worth having a close look at both of them. I remember going aboard a Sadler 29 and being concerned about how tiny the stowage bins under the berths were, and how, though it was a lovely sailing machine, I couldn't contemplate long-term cruising in one. I also think that to get to this "sail her home" or "recover from total flooding" state will require buoyancy of at least twice the displacement.
Twice in my sailing career I've been in a water over the cabin sole situation. The first was when I did a bad job of installing a paddlewheel log - so 100% peace of mind, which is what you seem to be aiming at, means taking it and glassing over the hole. Who needs a log anyway? The second was when I didn't realise that water was coming in through a ventilator in the anchor locker when I was bashing hard into a head sea. That could have resulted in loss of the boat if I'd not stopped in time, hove to and started to bail out. The proverbial "frightened man with a bucket" can do a lot more than a bilge pump can, particularly if there's debris to block the pump, but there comes a point of no return where it's impossible to get the water out faster than it's coming in. I believe that you would need more than twice the displacement in floatation to be sure of not reaching that point of no return.
I didn't put foam below the chine on Tystie because she's wooden, and visual inspection for deterioration is more important than it is for GRP. I wouldn't want sprayed on foam in a steel or alloy boat for the same reason, but maybe with GRP, getting someone to spray some foam on would be a lot quicker and easier than gluing on bits of sheet foam.
"I explained some of this plan to my friend Richard over breakfast. He has some very useful comments:
- Once the boat is insulated the amount of condensation appearing on the remaining cold spots is likely to increase: the hatch, the windows, metal frames, etc. Perhaps this is another good reason (apart from plan.osmosis-prevention) not to insulate below the waterline: cold surfaces in the bilge will act as a dehumidifier."
Yes.
Tystie has double glazed windows with no metal frame, and the washboard is a ply/foam/ply sandwich, but that still left the alloy-framed perspex deck hatch as a major source of drips. It needed secondary double glazing in the winter. An alloy mast will need a nice knitted jacket, as Arne has on his. There was much more condensation right out in the ends of the boat, where there was little heat and ventilation. But I don't buy using the bilge as a dehumidifier. Good ventilation is important to keep condensation at bay, and I suggest one or two Air Only vents.
Trying the Jester Challenge, eh? I thought about doing it in Weaverbird, and decided tha I couldn't carry enough water, though a stop in the Azores or a hand pumped watermaker would fix that. But in a smaller boat, half full of foam, austerity would be taken to a whole new level.