Seacocks - When to Close Them

Had 5 seacocks; now have 2. One for water in and one for waste out. Waste will stay closed unless used. Water in will stay open but exercised every time I check the oil (daily when cruising). Both seacocks and all associated plumbing are new except the strainer. As others have said, bilge pumps capacity far in excess of seacock flow and good insurance.

Ted

Leave mine open all the time. Only close for maintenance. They are stroked every month or so. Hoses are in good shape, and good hoses don't just fail out of the blue. All are accessible for viewing, no hoses carrying sea water run in hidden areas.

Ski in NC said:

... good hoses don't just fail out of the blue. All are accessible for viewing, no hoses carrying sea water run in hidden areas.

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My style of safe operations.

We have 3 thru hulls w/seacocks; one per engine/strainer, & one for the head intake. Close them all when leaving boat, open during pre-start check. Solves exercise problem as well.

Like the look of Bligh`s avatar? Leave`em open.

Seems to be a west coast/PNW/Aussie thing to close them. Here on the east coast it seems quite uncommon to close sea cocks.

Don't know about the PNW thing. Everyone I know in our marina (who I've asked) with either a power or sailboat leaves them open all the time. A lot of this has to do with the ease of getting to them.

I leave mine open, except for when I'm cleaning filters. But during refit all were serviced, some replaced, and all were fitted with new hoses and good quality double clamps so I have confidence in the integrity of the systems. I filled in 12 holes in the bottom during refit, some from when the PO used to have seawater heads, some from defunct transducers etc.

I haven't been doing monthly operation of them but that is a good idea. I'm on the boat every other day, and check the bilge pump cycle counter each time I board.

With slight bit of work a sea cock can be connected to a remote handle.

Tags dont work well, but hanging the engine or noisemaker start key on the valve handle works every time.

WE used to have to do it for a remote shaft lock .

Leaving the sea cocks open simply requires replacing hoses on a PM sked..

psneeld said:

Or just keep your seacocks and hoses in top condition, only have a minimum of them and keep strainers and pumps so near the waterline a leak is a trickle and not a flood.

Then even the wimpiest of bilge pumps will keep up...but have 3-4 robust ones and sleep well..whether your seacocks are left open or closed.

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Yup! Boating is enough work without being paranoid.

With an open seacock, I have a single point of failure (an upstream hose, clamp or fitting) keeping my unattended boat off the bottom. With seacocks closed, both the seacock and some other upstream failure would have to occur before the boat would sink, no? I'm not counting 1) a freeze burst or 2) a bad through-hull install/leaking adhesive, which would probably be a low-flow leak. What am I missing here?

Freeze protection is a different issue. If you can get exposed to freezing temps below deck, that brings on a whole new set of precautions.

Also, if you are going to leave the boat for months, then it can make sense to close things off. If it gives peace of mind, why not.

Mine runs at least once a week, so it's a different scenario. I use mine often as a second car, nice being able to chuck a shore cord, turn a key, four lines and be on my way.

I close mine, incl engine seacocks.

As per another poster, I hang the engine keys near the seacock when I close them. Simple and means there is no chance of starting the engines with them closed.

If you are really anal about your seacocks, and have a lot of money, GROCO makes motorized seacocks, close to $1K each. You can find similar remotely operated valves much cheaper from non-marine suppliers. If your seacocks are hard to get to, a company called T-H Marine sells "remote operation arms" for seacocks. Haven't tried either as ours are all pretty easy to get to.

Way to much paranoia here. Good maintenance and insurance is all you need. I've got numerous seacocks all over the boat. I'd need a check list and an extra 45 minutes each way if I followed this rule. Just a minute Dear I need to rip up the saloon floor before we leave. What? You ripped it up when we got here 3 hours ago. Somehow I don't think it's worth the effort.

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If a hose is not under pressure, like the engine intake or the air conditioner or the genset, if the hose clamps fail....I will bet the hose won't leak a drop...well maybe one every once and awhile and only if way below the waterline.

Seriously...learn where the real threats are and stop worrying about the 1 in a million.

psneeld said:

If a hose is not under pressure, like the engine intake or the air conditioner or the genset, if the hose clamps fail....I will bet the hose won't leak a drop...well maybe one every once and awhile and only if way below the waterline.

Seriously...learn where the real threats are and stop worrying about the 1 in a million.

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Yep - you try getting the baskets off, even after the hose clamps are removed. Ever manage to pull one off without using a tool or cutting a slit..? Ok…there's bound to be some one...

psneeld said:

Seriously...learn where the real threats are and stop worrying about the 1 in a million.

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From 2008 BOAT US analysis of "Why Boats Sink at the Dock."

In 50% of dockside sinkings, water found its way into the bilge through leaks at underwater fittings. The majority of the leaks are at stuffing boxes, followed by outdrive or shift bellows, failed hoses or hose clamps, sea strainers, and drain plugs.


Hardly one in a million.

angus99 said:

From 2008 BOAT US analysis of "Why Boats Sink at the Dock."

In 50% of dockside sinkings, water found its way into the bilge through leaks at underwater fittings. The majority of the leaks are at stuffing boxes, followed by outdrive or shift bellows, failed hoses or hose clamps, sea strainers, and drain plugs.


Hardly one in a million.

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You'll notice hoses,strainers are at the bottom of the list. Stuffing boxes and out drive bellows at the top. Back to maintenance again. Also what are the actual numbers ? Saying 50% of sinkings sounds like a lot but in reality may only be a 100 boats a year. Which is a much smaller % of the population.

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mbevins said:

You'll notice hoses,strainers are at the bottom of the list. Stuffing boxes and out drive bellows at the top. Back to maintenance again. Also what are the actual numbers ? Saying 50% of sinkings sounds like a lot but in reality may only be a 100 boats a year. Which is a much smaller % of the population.

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Whatever; it's not negligible. Part of my maintenance routine is shutting the seacocks when I leave the boat. Piece of cake with the sea chest on our Defever and I sleep better.

One sinking is one sinking too many for me if it`s my boat.
Too easy. Visit the ER, swing 3 handles 90 deg, same time as I check the Racor bowls. Plus the head, outside the ER.
Nearly forgot, had to slide the lock collars on each of 4 handles.( Unintended "Two Ronnies" joke embedded there).
Seriously, little effort to remove a risk.

angus99 said:

Whatever; it's not negligible. Part of my maintenance routine is shutting the seacocks when I leave the boat. Piece of cake with the sea chest on our Defever and I sleep better.

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Ah, now the truth comes out - you can do that because it's so easy - one sea chest to access and close. So, yeah….keep on doing that, because it makes sense in your situation.

However, I draw the line at having to do what mbevins rather colourfully described below as what his coming home with a hot engine room routine would mean to do that, because it describes what I would have to do also…

"Just a minute Dear I need to rip up the saloon floor before we leave". "What? You ripped it up when we got here 3 hours ago."
"Somehow I don't think it's worth the effort."

In my case, a detent in the handle, now under the engine room floor anyway, (se pic post 13) prevents me putting an extension on it and activating it from further away, especially as they installed it with the handle movement across the beam instead of fore & aft, like the one it replaced was. That said, the thruhull, strainer and hose are all new, so it's a statistical likelihood thing really.

psneeld said:

If a hose is not under pressure, like the engine intake or the air conditioner or the genset, if the hose clamps fail....I will bet the hose won't leak a drop...well maybe one every once and awhile and only if way below the waterline.

Seriously...learn where the real threats are and stop worrying about the 1 in a million.

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Guilty. I rarely exercise my seacocks except on maintenance days. Engine and genset more often. I'd love to have a sea-chest setup, Photoshop below ordered by Bruce.

healhustler said:

Guilty. I'd love to have a sea-chest setup,

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They're pretty cool. There are 8 through hulls on our sea chest (two of them not used), which makes operating the valves a breeze. I may change out the old yellow-handled seacocks this winter since they no longer make parts for them.

angus99 said:

From 2008 BOAT US analysis of "Why Boats Sink at the Dock."

In 50% of dockside sinkings, water found its way into the bilge through leaks at underwater fittings. The majority of the leaks are at stuffing boxes, followed by outdrive or shift bellows, failed hoses or hose clamps, sea strainers, and drain plugs.


Hardly one in a million.

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Of boats that sink....and claims put in or reported to USCG....many are not.

I have helped raise hundreds in the last couple of years for an assistance towing company...I disagree with a bunch of those investigators...and I have accident investigation training from several prestigious universities....not the school of hull tapping.

I work with a guy who is up there...almost a pathologist in boat sinkings....it is easy to say hose clamp when it is way more complex but you get paid the same for a one page report or 30 pages.

Sorry....but while the BoatUS report has its place, it is far from painting a clear picture.

Read what you posted....shaft packing and outdrive bellows....hardly anything a seacock will help.

Also the pics that BoatUS shows of failed hoses and clamps are not what my equipment looks like. I check things very well annually, combined with several good visual inspections thru out the season so failed components due to being old is not on my agenda.
I'd rather spend my time worrying about whether I have enough ice.

angus99 said:

They're pretty cool. There are 8 through hulls on our sea chest (two of them not used), which makes operating the valves a breeze. I may change out the old yellow-handled seacocks this winter since they no longer make parts for them.

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I'd plug the unused one on the right and remove the handle. You could easily hit the handle. With no plug and you wouldn't even know it till the bilge pump went on or heaven for bid, the pump failed and ....

OK, guys. Whether it's a frequent or rare cause of sinkings doesn't matter to me. A friend who is a lifelong blue-water sailor used to tell me the best sailors he knew always treated their boats like they were trying to sink from under them--whether underway or at the dock. We all choose what to worry about and I choose not to worry about potential water intrusions from hose failures, etc. by shutting the seacocks while I'm away from the boat. I'm aware that there are are other, more likely causes . . . but if the worst happened it is not going to matter to me that there was a .00001 percent or 10 percent chance. It's a 60-second job for me and a total no-brainer.

Larry M said:

I'd plug the unused one on the right and remove the handle. You could easily hit the handle. With no plug and you wouldn't even know it till the bilge pump went on or heaven for bid, the pump failed and ....

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Thanks, Larry. Good advice. It's an old photo; it's plugged now.