Cock Pit Drainage

[Allan Jennings]

Having nearly finished my boat ( 53 ft) I realise that if my centre cock pit is swamped there is no where for the water to go. OK for the foot well, I have two 2" dia dains but looking at the overall cock pit that dosen't seem nearly eanough. Does anyone know how to calculate how much water goes through a 2 " hole under gravity. What is the maximum time you should be flooded for? I feel an idiot as I designed the cock pit so that the seat backs kept the water out in most weather but if I get really pooped then the water is stuck and only the duck boards in the entrance will keep the central pilot house dry, which won't be for very long!!

[Raggi_Thor]

There are several rules for this, the volume of your cockpit may be more critical than the size of tha drains. See for example http://www.phrfchesbay.com/eastdscert.pdf :

6.23 Maximum cockpit volume below lowest coaming shall not exceed 9% of LWL x Max Beam x Freeboard aft.
Cockpit sole shall be at least 2% of LOA above LWL. (Sailboats built before
January 1980 shall not be required to retrofit provided that their maximum cockpit volume does not exceed 12% of LWL x Max Beam x Freeboard aft.)

[FAST FRED]

Fill it with a hose , and time the drain.

5 min is barely acceptable and 3 min is lots better.

Waves come more often than that,

Some boats can drain aft with big scuppers similar to "racing" sailboats.

3 sq ft of scupper on either side would not be too big.

FAST FRED

[Raggi_Thor]

That's i nice practical approach Fred :-)