Seacocks Open or Closed while sailing?

Stu Jackson · May 28, 2013

Some boats have different "conditions" than others. For example, the Catalina 36, a great "buddy" boat like ours, has a forward head and head sink. When on port tack the head sink is reported to fill with water unless the seacock is closed. We have a midships head on the port side, never had an issue.

Head inlet: all manufacturers have (or should have) placed a warning to close the head seacock after the head is used. We never do, and have never had a problem in 15 years.

We open all our seacocks (except the head out - we use the holding tank) and close them all when we leave the boat.

Your boat, your choice.

Nodak7 · May 28, 2013

YVRguy said:
Curious as to common practice, particularly among Hunter 34 owners. I was advised by the previous owner to close the seacock for the head while under sail and possibly the sinks as well. The obvious reason being to prevent backwash from coming up into the cabin.

I occasionally take the time to close them but I don't seem to have much of a problem if I leave them open. What do you folks do?

As Stu said each boat is unique. When we were well heeled to Starboard the sink in the Head would fill on our 33. This boat no issues. Only close the seacocks when in Port.

RichH · May 28, 2013

My practice:
On long distance passages and ocean travel ---- all seacocks are closed; and, bilge is inspected ~hourly and even that I have a 'high water' alarm).
Storm conditions - all seacocks are closed (except seacocks for bilge pumps).

Inshore - all open, as I can always run the boat up and hard aground onto a shore if absolutely need to.

;-)

Mark48 · May 28, 2013

We have had the unpleasant experience of having our head fill on occasion and thus close that and all other seacocks except for motor cooling water. If a sink needs drained it can always be opened and reclosed.

Don Lucas · May 28, 2013

different boats different needs, I never shut them on my current boat

but my last boat when on stbd tack the head would fill up, so I installed a separate ball valve in the line next to the head so it could be shut to prevent it

the last thing I would want to have to do each time is get to a seacock just to take a pee

Mulf · May 28, 2013

Close every thing but engine thru hull...

...when moving the boat. Our forward head has thru hulls about 5 feet from the bow. Imagine the water forced into that thru hull and the hose attached to it when you go airborne over a wave and come slamming down the other side! I'm not interested in testing the strength of the hose or the two clamps that way. The rest of the thru hulls on our boat are behind the keel so probably much less worry, but we close everything not in use, so there's no worry. As to Don's comment about being able to use the head, I installed a freshwater tank behind the aft head so it can be flushed without opening a thru hull. Other solution would be a bottle filled from the sink for flush water.

kloudie1 · May 28, 2013

YVR.. I don't close the seacocks on my 34 when at sea.. I haven't had a problem in the 22 years I've owned and sailed her.I do carefully inspect all the hoses and hose clamps every year. I do watch the head to make sure that the flush and vent valves are working correctly. I also check things like the sink connection to the drain hose. The tee on that hose and the hose end on the head sink are tied with light line so that if the carbon steel sink outlet breaks off, the hose cannot fall below the waterline. The only time I close the seacocks is when preparing for a hurricane.

Pat Hooyman · May 28, 2013

I guess it depends on just how much you believe in Murphy's Law. It is a pain but can't hurt to close them - just make sure you open the raw water valve for the motor!

splax · May 28, 2013

Personally, I am comfortable with the sink drain through-hull valves open underway, but I suppose there is the chance of a hose failure. The head may fill with water if the switch is not in the dry bowl position, so I keep the through-hull valve closed underway if not in use. If sailing, I may close the raw water engine cooling valve if it is rough. Head discharge always stays closed.

Benny17441 · May 29, 2013

Easy, run your boat with the seacocks open; if you do not detect a problem on either tack you may choose to leave them open. Inspect your hoses and clamps at frequent intervals for safety concerns. I only close them when the boat is left unattended as the electric convenience bilge pump will not be able to keep up if there is a significant failure.

Claude L.-Auger · May 29, 2013

I generally keep them opened and have not had any problems except for some gurgling from the forward vanity sink drain when on a hard starboard tack. Also with guests aboard I need to make sure the lever is in the dry bowl position as the bowl itself is 2 inches below the water line and if overfilled it willl sink the boat! I was lucky to be awakened in the middle of the night by the sound of the bilge pump running non-stop. A quick check showed the lever had been left in the wet position by a guest who used the head during the night. So I now close the through-hull seacock during the night and ask guests to pour water in the bowl when flushing. I have had 2 dock neighbors sink because of faulty hose clamps. So I make it a habit of closing all seacocks (including engine intake) when away from the boat. I leave the key on the engine seacock so I cannot start the engine and have it run dry.