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9407 12-22-2004 07:51 PM

i have just purchased my first boat and was hoping to get an answer to this q?the cockpit scuppers in my boat are connected to a valve and then thru fitting. is there any specific route they must take eg.(a loop or ?)in order to drain efectively or is the best route the shortest and straightest?

svzephyr44 12-23-2004 03:47 AM

Shortest is best. Make sure they stay clear. Stuff that accumulates in the cockpit (we had a problem with dead bugs and leaves) can get down into the hose and clog it up. BTW, the valve is most likely on the thru-hull. Its purpose is to close off the thru-hull if the hose breaks so that you don''t sink! Some people choose to close all the thru-hulls when they leave the boat. In the case of the cockpit thru-hulls you are a little dam*( if you do and dam&* if you don''t. If you close them the cockpit may fill with water (not good), if you don''t a hose could break (unlikely if your maintenance is good) and the boat could sink!

TrueBlue 12-23-2004 07:33 AM

The thru-hull outlet for the cockpit scupper drainhoses should be positioned above the waterline. The hose route should be positioned such that when heeling, gravity will still allow the cockpit to drain.

jkumin 12-23-2004 10:42 AM

Like everything with boats there are pro''s and con''s with different routing. Having the drain go to a through-hull with seacock lets it be placed directly under the cockpit well for a short direct route, quick to drain and less likely to clog. Below the waterline discharges avoid topsides staining from water dribbling down. On the other hand they are one more hole in the boat that should be left open while away. If closed the cockpit can fill with water from rain or snow, which will eventually find its way below.

Since you already have the below waterline setup, I wouldn''t change. No need to loop the drain. That''s done for anti-siphoning, not a problem with cockpit drains. Keep the run short and direct, use really good hose, double clamp at fittings, and check it periodically. That includes opening and closing the seacocks to make sure they still work.

Jeff_H 12-23-2004 12:28 PM

I am deeply opposed to cockpit drains that exit below the waterline on any boat that may be left in the water over the winter in a northern climate. The cockpit drains need to be left open during the winter and if they are in the water sooner or later the lines will freeze up and split the drain hose. It is bad enough to have a frozen cockpit drain leaking into the boat but it is way more serious if that hose is attached to a thru-hull below the waterline.


jkumin 12-23-2004 01:18 PM

There was no mention of the boat being left in the water over a winter. Given that, Jeff''s point of it being a risk is correct. However, I have left a boat in the water with below the waterline cockpit drains for many years in Alaska. Our harbor is full of boats like that. In my experience rubber hose doesn''t split if it freezes - it expands slightly then contracts when the water thaws out. I always wrapped the drain lines and seacocks with electric heat tape to keep them warm as an added precaution. Granted there could be a prolonged power outage at the same time as a very deep freeze. If you want to avoid all risks of sinking better pull the boat. I have seen boats sink from seacock problems but it''s always the same stuff - a seacock eaten out by electrolysis or an old rotten hose.

DelmarRey 12-23-2004 03:38 PM

I would concur with Jeff on this one.

On the other hand they would be no differant than a regular thru hull except that there would be water running through them no matter what the boats status is, that is being out in the weather. And when rubber gets cold it gets harder and can break.

Personally, I would re-design them so if they were below the waterline, and and if the hose failed they would not take on water.

By glassing or plumbing in a stack, the hose connection is above the waterline. This way if there is a hose failure it''ll still hold water. But still allowing it to drain, in the water or not. Kind of like your rudder support/bearing. If they''re plumbed in (thruhull fittings), they will still have to be maintenanced just like any other thruhll.

You wouldn''t need the seacocks either. It would take a catastrophe event to make them leak. Then you''ll have more to worry about then just your scupper drains..........._/)

Jeff_H 12-24-2004 06:42 AM


What you are suggesting is against ABYC recommendations. All below waterline thru-hulls should have a seacock and rigid portions of a plumbing system are more prone to bursting than rubber hoses which often have some give to them. Again I strongly recommend that the cockpit drain overboard discharge be above the waterline on any boat likely to be in the water in a freeze prone venue.


DelmarRey 12-24-2004 08:13 AM

So what does the ABYC say about the exhaust ports on power boats. They''re
submerged or at least partly!

elhanley 01-04-2005 03:28 PM

If a cockpit drain is run straight down, and the boat heels far enough to place the drain inlet below sea level, water will flood up the drain to sea level. For that reason, they are usually run across the boat to exit the hull above sea level when heeled, or at least minimize the depth to which they are submerged.

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