Check your thu-hulls

[Ozzie]

I try to follow the motto, “the comfortable we do today, the difficult we put off till next year”

The only unsinkable boat is supposed to be a Boston Whaler, who’s advertising blurb included cutting the boat in half and driving away with the bit with the motor. The comfort factor in that bit was fairly low though I’d say

[Peter T]

I remember years ago seeing a hood completely sitting upright on the bottom of the Tamar River with just the top of its mast sticking out of the water. Apparently it had a depth sounder sender in the bottom of the hull. Lightning hit the top of the mast and electricity will always take the path of least resistance to earth. In this case, that was through the electrics of the boat to the depth sounder sender unit. It blew a hole straight through the sender unit and sunk the boat in the middle of the night while the boat was on its mooring. Perhaps a chain wrapped around the mast and hung over the side into the water to a depth deeper than the bottom of the boat may have prevented this. On my last boat I had the sender unit mounted on the inside of the hull in a fibreglass tube filled with oil and the hull was not drilled to fit the sender unit. I often used to wonder if lightning would still blow a hole through the hull with this set up. Luckily, I never found out. Either that or it worked ? Should not be a problem with the boat on its trailer parked in the shed and I would only sail in an electrical storm if I got caught in it and had to.

[Ozzie]

Wasn’t sure if I should put this in the “today at Valentine “ or “check your thu-hulls” .

This thread won .

[Andrew]

Came across this video from LadyK sailing, anout how easy it is to sink via though hull failure

https://www.youtube.com/watch?v=XkAsfunh7HM

It's amazing how much water can come in through a paddle-wheel hole. (Their auto-electric bilge pump didn't work, so it's a good measure of the unattended "sinking rate" in this video)

[Ozzie]

Scary stuff Andrew As I mentioned once before my only through hull was the paddle speed log which I siliconed up permanently when I moored Spritzig II. I might fair it over with epoxy next haulout just to be sure after watching that.

I’ll never Bluewater sail but I think I’d have things like passports, paper money, documents etc in plastic and permanently in my grab bag which I’d have right near the companionway if I did. It’s frightening to read how quick some boats go down. The last thing you’d want to distract you from either saving the ship or safe egress would be a packing list.

I know little about it but the engineer in me would think there must be a design that incorporates all entry and exit points from a boat hull that could start above the waterline. Maybe have a double wall transom and run everything down through the cavity.?

If science can fly a ship to Mars we can design that

[IanS]

Been thinking about this stuff for under the bunks and vee berth, but I think I'd want to get some down near the stern as well.

https://trojanfibreglass.com.au/product ... am-liquid/

Ian

[Ozzie]

I have used white packing foam slabs and glued them together with spray can foam from the green shed Ian. Works ok. I filled the space created by the rear keel shape under the cockpit floor that way, as I kept loosing stuff in the hole. Also used the same technique to take up space in my bucket that I use to flush the motor on the mooring. The foam mix is expensive but good. The slab foam just means you need less.

Let us know how you go

[IanS]

Thanks Ozzie,

I read an article about an aluminium yacht that put the expanding foam between the hull and the cabin sole, and in various other places. When they foundered on a reef it punctured the hull but the boat didn't take on any water because of the foam lining the hull. They floated off on the next high tide and didn't realise they had a hole until haul-out.

Obviously, there is not that much space in an Investigator.

[Peter T]

As you may know, I removed the lead each side of the centreboard case to make the fibreglass repairs on the inside bottom of my keel. When I re - fitted the lead, the space around the lead got the expanding foam treatment before being epoxy fibreglassed over that. There will never be water in my lower bilge again, I can guarantee that.