Seacocks - to close after sailing or not?

Sep 24, 2016
17
Hunter Cherubini 30 Cayuga Lake
So, the Cherubini is my first boat with Seacocks. They were all replaced last fall (by the Marina), so I am confident they are not leaking (yeah - right)! :what:


I also sealed with 3M 5200 around each thru-hull before bottom painting. :cool:

My question is...

The Engine manual says to close the Engine Seacock after sailing, and open it before sailing. Is this necessary? Access to my Engine is not the easiest thing. Also, do you recommend closing the gray water seacocks after docking, even if you plan to go out the next day? I suppose it is a safe thing to do if staying overnight... :snooze:
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
I close the engine raw water intake. There are lots of seals and fittings here that can fail. A friend partially sunk his boat when raw water pump started leaking and his bilge pump failed.
 
Sep 24, 2016
17
Hunter Cherubini 30 Cayuga Lake
Thru-hulls and Seacocks... a new dimension to sailing after owning a day sailer! Thanks Les!
 
Mar 4, 2017
40
Hunter 27 Cherubini Seabrook, TX.
I have heard of those who close theirs after each sail, and those that leave them open all the time.

I'm of the mind that its better safe than sorry, so I always close mine. There's enough to worry about without worrying about something failing when I'm not on board.
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
I have heard of those who close theirs after each sail, and those that leave them open all the time.

I'm of the mind that its better safe than sorry, so I always close mine. There's enough to worry about without worrying about something failing when I'm not on board.
BINGO. Les is right, too.

I sailed our boat up the coast for six weeks. Never closed anything. I leave the boat at the marina to go home, everything is closed.

Simple: if you're not there, lock the door~:)
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
I have a big laminated sign hung just inside the companionway -- it reads "Thru-Hulls". Good reminder coming ad going. The admiral has a check list she has started ( one before leaving dock to sail another for leaving in a car). Very smart woman ( she married me didn't she)
 
Oct 6, 2007
1,023
Hunter H30 1982 Chicago IL
That's where I store mine. It reminds me to open it when I go out, and close it when I get in.
Me too. Engine key stored on the seacock lever. It's open only when we leave the harbor. All the others - head intake, lavatory sink and galley sink - are opened when I get to the boat on Friday and closed when I leave the boat on Sunday.

Access is not bad in my opinion. Worst one is the galley sink; under a lift out panel in the locker below the sink. Everything in that locker is stored in a lift out plastic basket so the panel is easier to get to.
 
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Jan 24, 2017
666
Hunter 34 Toms River Nj
Absolutely close all seacocks when you are done sailing for the weekend. I had a split in my raw water hose that I didn't notice untill I closed the valve. Also fellow boater partially sunk due to a faulty bilge pump and water pump seal leak. $32k later all could have been avoided if they shut off the valve.

As a reminder to turn on the raw water valve I put a labe on my ignition "open seacock" and key chain
 
Jan 18, 2016
782
Catalina 387 Dana Point
Always closed when not on the boat. Fuel valve too. So sometimes I've sailed out of the marina when I forgot to open the fuel valve. That's much better than coming to the boat and finding the bilge full of fuel (or worse, pumping it out to the harbor).

Same for all seacocks - can't sink the boat if it's closed.
 
Jun 21, 2007
2,105
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Distracted by guests once and having over-nighted at a guest berth, my normal seacock opening routine was disrupted. 10 minutes up the channel, the engine started to overheat. The impeller had run dry and self destructed. Fortunately, all did end well that day. A light wind and one crew member who could sail with just the jib up gave me the chance to remove the raw water pump and replace the impeller.

Vowing never to have that happen again, I cobbled together a "closed seacock" audible alarm. When starting the engine, if the engine alarm doesn't stop after a few seconds (when the oil pressure is OK), then I know the seacock is in the closed position. Picture of the setup attached.

Stretching myself over the lazerette seat coming to reach the seacock was difficult and very uncomfortable. Using PVC pipe, I made an extension. On the top of the extension is a PVC T-fitting which acts as the handle. Now no problem to open and close in comfort.
 

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Tom J

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Sep 30, 2008
2,301
Catalina 310 Quincy, MA
We close all seacocks when leaving the boat, even for a couple of hours. Raw water intake for engine is always closed when engine is not running, except when we are at anchor, and we are aboard. Several times I have had to start the engine in a hurry while at anchor, when winds exceeded 35 knots, as high as 55 knots. More than once, the anchor dragged, and I was glad the seacock was already open.
 

JSumme

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Jul 21, 2015
35
Marlow-Hunter e33 Alexandria
This is an interesting discussion for me. I have an Elko electric engine instead of a diesel. So my only seacocks are raw water for the diesel genset, raw water for the Heater/air conditioner and gray water drain for the sink. I also have a drain for the head's holding tank, but that stays closed because I'm on inland waterways. My A/C unit has a dehumidify setting that runs the A/C periodically in the summer when I'm not on the boat. Of course, that requires that I leave the seacock open so the A/C gets coolant water. All others can be shut until needed. Does anyone have this issue with running the A/C periodically to dehumidify the boat? Suggestions?
 

Alctel

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Dec 13, 2013
264
Hunter 36 Victoria
I only have two now, the raw water intake for the engine and the galley sink drain.

I close the engine one when not using it (like others, I hang my keys on it) and the sink one I leave open all the time, unless I know I am gone for a few days.
 
Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park
The Engine manual says to close the Engine Seacock after sailing, and open it before sailing. Is this necessary? Access to my Engine is not the easiest thing...
I installed a hatch in my stairway to make access much easier. Not the prettiest thing, but very functional.

image.jpeg
 
Aug 3, 2010
150
Hunter 326 Charleston SC
I leave the seacock for the AC open as well, it's in the dehumidify mode when off the boat. It's an accepted risk but needed in SC. I also have two bilge pumps, one low the other 3" up.
 
Sep 20, 2006
2,912
Hunter 33 Georgian Bay, Ontario, Canada
Close them for all the above reasons about leaks while you;'re off the boat. Also, not mentioned, if you don't use them, they will eventually seize up? You'll only discover this when you really need to close one....

You also should not have to install the 5200 on the outside. If they were installed properly there should not be any caulking showing.