Deck Drainage

[JohnF]

Ok looking for some ideas with a problem! I part own a Prosport 6.5 diesel inboard, this has a raised engine compartment at the back. There is a bilge pump in the bottom of the engine compartment for any water that gets in there. The deck however has two elephant trunks and two of the useless ping pong ball drains.

When still, as the boat is quite rear heavy, the back of the deck just fills up with water and only drains when you get on the move. My first idea was to cut two sumps into the deck either side of the engine compartment each with its own bilge pump. On looking again however whilst not impossible would be quite tricky as not a lot of space.

After a quick look at the boat the other day I came up with another idea, initially I thought about just draining it into the bottom of the engine compartment and letting that bilge pump get rid. My concern with this though was that probably ok most of the time but if you ever swamped the deck could flood the engine. So my next idea was to build a sealed box in the engine compartment with a breather pipe two drain pipes (one from each side of the engine compartment) and its own bilge pump. I could then replace the two ping pong drains with drain cocks that could be opened when out of the water and can still drop the elephant trunks if ever required.

Can anybody see any flaws with this idea or offer any other options that I haven't thought of. Cheers John

[gtflash]

I have flappy valves that also leak. See them on hundreds of boats and they are the rubber equivalent to ping pongs. I tried an additional NRV inline. Still leaked. I raised deck inlets to scuppers, still leaked.

I have separate bilge for shallow water and a low bilge in the v.

I bought springs for flaps and replaced them every year. In the end I bought some bungs that go in the inlet to scupper. Works a treat and cost about a fiver. I can see water in the deck drain tubes until I get going then they empty. Sometimes without the bungs she’s dry for weeks then another day it floods the deck. Get rid of ping pongs if you can and use elephants when needed. Or turn ping pongs into elephants.

None are full proof.

[Searider]

You could drain your deck (through a small drain) into one of these: https://www.force4.co.uk/item/Force-...-Sump-Pump/GB2

The keep the elephants trunks. As a belt and braces you could also have plugs inside the transom drains.

[paulbrown22]

Not that it helps solve the problem at all, but my diesel Ribtec seems to have been designed in such a way to prevent this, such that the deck sits above the waterline and under typical conditions at least can't take on any sea water. If it rains, fine, I get water on the deck, but if I let the elephant trunks down, the rain water empties without any sea water coming in given the height.

I've been on a few RIB's that seem to just take on water at slow speed, some so bad you actually got wet feet at the helm while slow manoeuvring. Personally I'd do anything to avoid those various valved contraptions that always seem to end up leaking and add some additional pumped drains, or given you have both ping pongs and elephants, just close off the ping pongs as the easy solution?

[JohnF]

Thanks Searider, that was basically what I was going to construct so would save me a bit of a job. Intend keeping the elephant trunks as well but only for use in big seas as normally boat stays quite dry,