Can Somebody Tell Me What This Is.
- Thread starter rob740
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The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
caltexflanc
Guru
It's called a sea chest , for intake and output of various raw water needs.
ben2go
Guru
Sea chest. If the top is above the waterline, the top can be removed and any obstructions cleared by hand. They have some benefits but if the top ever blows out, she's going to the bottom in a hurry.
RT Firefly
Enigma
Greetings,
Welcome aboard. Yup, sea chest. The purpose is to eliminate all but one penetration through the hull for cooling (sea) water thus eliminating multiple, potential sources of leakage (seacocks).
Welcome aboard. Yup, sea chest. The purpose is to eliminate all but one penetration through the hull for cooling (sea) water thus eliminating multiple, potential sources of leakage (seacocks).
Thanks everybody,, A sea chest on a pleasure boat that's pretty cool,, But looks scary if that top blows off.
The boat has been sitting for 3 years in the water i should probable take the cover off and do a clean out before i start it up.
The boat has been sitting for 3 years in the water i should probable take the cover off and do a clean out before i start it up.
rslifkin
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Judging by the design of it, I wouldn't say that reduces leak points at all (being that the seacocks enter it below the water line), but it does allow for in-water cleaning of intakes if the top is above the waterline, which can definitely be useful in some areas.
RT Firefly
Enigma
Greetings,
Mr. r. So....You've purchased this vessel? You're doing service on it? Thinking of buying it? The world wants to know!
Mr. r. So....You've purchased this vessel? You're doing service on it? Thinking of buying it? The world wants to know!
wkearney99
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So, what, there's a big-ass rectangular opening in the bottom of the hull under this? Or there's just one intake in the otherwise regular hull bottom surface?
dhays
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I think a sea chest would be great to have, if was designed correctly. I believe the Great Harbor 36 has one? Maybe the N37 as well?
Tuttouomo
Senior Member
Sea Chest
The sea chest on my DF44 has a 1" thick piece of Lexan material as the cover, and is through bolted through the bottom flange with 3/8 s/s bolts & nuts, 3" on center. I don't think it is readily going to " blow off" and sink the boat.
Most of the Defevers have the sea chest top just above the water line. If we are fully loaded with fuel, water and supplies, the water level is right at the top.
To the OP, if you are considering buying this vessel, I would factor in upgrading and replacing all the thru hulls and sea cocks on that sea chest. From your pic, it seems as though there are some elbows attached to the thru hulls and then the sea cocks ; a point of failure.
Bill
The sea chest on my DF44 has a 1" thick piece of Lexan material as the cover, and is through bolted through the bottom flange with 3/8 s/s bolts & nuts, 3" on center. I don't think it is readily going to " blow off" and sink the boat.
Most of the Defevers have the sea chest top just above the water line. If we are fully loaded with fuel, water and supplies, the water level is right at the top.
To the OP, if you are considering buying this vessel, I would factor in upgrading and replacing all the thru hulls and sea cocks on that sea chest. From your pic, it seems as though there are some elbows attached to the thru hulls and then the sea cocks ; a point of failure.
Bill
RT Firefly
Enigma
Greetings,
Mr. r. Thanks. A good survey should give you more information to base a decision on. Perhaps even a quick (cheap) walk through by a qualified surveyor may determine whether or not it would be wise to proceed. Spend a few $$ to possibly avoid a costly mistake.
Do you have any boating experience?
Mr. r. Thanks. A good survey should give you more information to base a decision on. Perhaps even a quick (cheap) walk through by a qualified surveyor may determine whether or not it would be wise to proceed. Spend a few $$ to possibly avoid a costly mistake.
Do you have any boating experience?
Yeah i plan on getting a quick survey. Most of the surveys i have had really did give me any good info and i actually found more things wrong then the surveyor did.
Yes i have 30 to 35 years of boating experience mostly sail but were going to the dark side now. my crew has gone its separate ways so it just me and the wife.
Yes i have 30 to 35 years of boating experience mostly sail but were going to the dark side now. my crew has gone its separate ways so it just me and the wife.
motion30
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Yes a sea chest
You fill it with ice and then store your beer there
You fill it with ice and then store your beer there
Knot Fast
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Good for fishing on rainy days, too...
OldDan1943
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LOL Stop that. He just might follow your advice.
If the water is fairly clear and shallow, you can look and see the bottom.
Lepke
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In ship and big boats there are usually two sea chests - intake and outlet. In steel boats it's usually a large pipe 6" or more with a gate valve on the top for easy opening. In port, bleach can be poured in to keep down any growth. Air pressure can push the water out. Some boats have their deck & cabin top drains plumbed to the sea chest.
In a battleship, the sea chest is about 6' across.
In a battleship, the sea chest is about 6' across.
healhustler
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Right you are, Dave. As far as I know, all GH trawlers have it.
Attachments
ksanders
Moderator Emeritus
I’m not so sure I see any advantage to a sea chest over seacocks just bolted to the hull, at least not in the two examples I have seen photos of in this thread.
so what (other than saving floor space I suppose) is the advantage of a sea chest again?
so what (other than saving floor space I suppose) is the advantage of a sea chest again?
Lou_tribal
Guru
One main advantage it allows to launch your underwater bomber drone without being seen!
L
L
Comodave
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The big advantage is being able to clean out debris with the boat in the water. The problem is removing the lexan cover, a lot of bolts to remove but doable. So some people put in access ports in the lexan so they don’t have to remove all the bolts. The problem with an access port is they are not as secure as the solid lexan. They could blow out in heavy seas... maybe.
OldDan1943
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The top of the sea chest is at least a foot above the water line.
Comodave
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It does not look like the top is a foot above the waterline because the intake appears to be within a couple of inches from the top. It would be sucking air if the water is a foot from the top.
Also agree that some of the through hulls have a 90 before the shutoffs. What happens if the 90 degree fitting has a failure? I would like to see the shutoffs first in line from the sea chest so if you have a failure in a fitting or hose you can shut off the water flow.
Also agree that some of the through hulls have a 90 before the shutoffs. What happens if the 90 degree fitting has a failure? I would like to see the shutoffs first in line from the sea chest so if you have a failure in a fitting or hose you can shut off the water flow.
dhays
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One big advantage is that all your thru hulls are in one location. I don't close all my thru hulls all the time. The only reason for that is the inconvenient of crawling all over the boat closing them all. If you look at that photo of the GH, that sea chest has easy access and you can close them all easily.
Second advantage, not so much for us in colder water, is it is easy to clean out the thru hulls. Open the top, and reach down to clear out any debri or growth from the thru hulls. This of course means it has to be well designed.
There are disadvantages as well, I think the primary being that you have longer hose runs for your raw water intakes in most cases.
Lepke
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Pipe sea chests usually have a valve top and bottom. So you shut all the valves attached, push the water out with air pressure, close the bottom valve and do whatever maintenance you want.
catalinajack
Guru
No, the top of the sea chest on most DeFever 44s is right at the water line. Mine is and I very much like having all my through hulls right there. Plus, the likelihood of any one through hull getting plugged up is greatly reduced.
