Tuesday 9 June 2009

That sinking feeling

One thing I thought might be useful to know was how much water my Light Trow could take on board. To that end I loaded the boat with gear, closed the lockers tight and sailed out to one of the large yellow buoys that separate the designated bathing and boating zones. The buoy was anchored in 3 or 4 metres. If I’d had any serious doubts about the boat’s buoyancy I wouldn’t have carried out the test in such deep water but just in case she sank I tied her to the buoy with a very short line. Then, with lively curiosity, I undid the drain plugs.

It’s difficult not to be alarmed at the sight of water gushing up from the bottom of the boat. The family had already deemed me bonkers and now they watched from the beach waiting for the big glug glug. I put on my life jacket and patiently waited as the water rose about my ankles.

It rose and rose. Then stopped just where I expected it to—at the height of the central thwart. I moved to the stern of the boat to check that water had stopped coming in through the aft drain plugs and noted that the boat seem considerably less stable than when empty. Unfortunately I hadn’t secured the masts in their steps so couldn’t risk testing the limits of stability for risk of capsize. (My main fear in the event of capsize is that the mast foot will come out of the step and that the mast will then lever the deck off. I have since made a foolproof system of securing the masts.)

Back on the forward thwart I decided that OB could still take more water. We’d had water up to the central thwart when a wave came aboard on our trip to France last year but there was still room for more. Quite a lot more it transpired, and I fairly tired myself out trying not to compromise stability while filling buckets over the side and tipping them into the boat.

A swimmer approached, he’d just swum 200 metres from the beach and I hoped he wasn’t going to tip us over by holding onto the gunwale for a rest. ‘Fishing are you?’ he asked, closing with OB. ‘No, just trying to sink my boat.’ I replied giving him the wild-eyed, suicidal look I reserve for these moments. ‘Oh, I’ll leave you to it then.’ He said moving away with a strong backstroke.

I reverse bailed until the water was up to the side decks amidships. As the boat tipped slightly with the waves it emptied itself of some water and refilled again with the next wave. I considered OB full and, seeing that she’d regained stability raised the centreboard. If I moved to the stern water drained out through the centreboard trunk and if I moved my weight from side to side water alternately sloshed aboard and then sloshed out again.

The boat was low in the water, awash amidships but with the bow and stern still proud. I sat on the foredeck and considered. I hadn’t expected her to be quite so sub-marine. There was built in buoyancy fore and aft, then the fenders under the forward thwart, but maybe I should have buoyancy bags under the aft and centre thwarts as well. The day was calm, there was no wind or waves to speak of and bailing was easy. But in more severe conditions with waves, would I be able to empty the boat? Maybe. With the boat riding to a sea anchor and me bailing from the stern to keep the bow high.

Having emptied the boat I opened the lockers and was disappointed to find that water had seeped in both front and back. I assumed that this was due to the hatch seals but there’s no sure way of knowing short of inserting a Lilliputian with a torch and camera in the locker and filling the boat with water again.

So, I’ll get some more buoyancy around the aft thwart and, bearing the rest in mind, will try not to sail in such a way as to provoke a serious swamping.


Ben said...

Apologies for the lack of posts over the past month. I managed to cancel my internet connection and have spent the past five weeks in a web user’s purgatory—being charged by two companies while receiving service from neither.

AnalogKid said...

Good to have you back Ben, I kept checking every day, just in case.

RyanC said...

With the boat out on dry land you could pour water into the lockers and check for leaks. Then to test the hatch seals turn the boat over and see where/if the water leaks out.

Thanks for all the great posts that have let me live a little vicariously until such a time as I can make my own boat.

Ben said...

Nice idea RyanC. Also a good way of cleaning the lockers.

Gavin Atkin said...

You might also consider my original idea of boxing in the forward section of the boat...

But bouyancy bags are certainly an option.

How is it going with your exploration of the rudder issue?


Ben said...

Yes Gav, boxing in the centreboard case is something I feel I should have done when I was building. I suppose it's not too late but I have got used to using the boat as it is.

I didn't finish making the T-piece rudder. I finished the other one first and it works fine, better I think than the three previous ones.

I'm still without internet so haven't posted my findings or my extensive preparations for this summer's cruise.

I'll be trailoring the boat south to Valencia then sailing north on the prevailing southerlies.

Hopefully I'll have a connection when I get back and can post a report.