Do you have thru-hulls above water line?

[bcboomer]

I was told that a sister ship to mine sank at the dock because a deck drain hose clamp had failed at the lower end. There was enough chop from the stern to slop a little water into the boat with every little wave. Eventually it was low enough to flood in.
A lesson to inspect all the clamps and give them a tightening twist.
When I bought my boat there were several clamps that appeared fine but snapped when torqued a little tighter.

[Minggat]

So the boat had an exhaust system that could flood the boat if a hose were disconnected at at least one end, no adequate bilge pump (not to mention alarmed), and some thru hulls above the waterline that the live aboard might have opened and closed as needed (if they had sea cocks), and the last contributing item is culprit?

On my last haul out, I removed 3 thru hulls below the waterline, and relocated 2 of those above the waterline. One of those had a bad valve in that I had no idea that them stem was not turning the ball.

Those that got relocated above the waterline are cockpit scupper drains. So no valves.

Boats are vulnerable. Only made more so by bad design or poor maintenance.

[gmakhs]

All my bilge pumps through holes are above the waterline near the deck level

[GordMay]

Originally Posted by longjonsilver

Its been said that more boats sink at the dock than anywhere else.
Hmmmm

Remember: At sea, a boat is [almost ] always manned, whereas dockside it's mostly unattended.

More than two-thirds of the reasons why boats sank could be considered preventable. Half of those preventable claims, or one-third of the total, involved boats that sank due to the gradual failure of a part below the waterline.
And, according to BoatUS records, for every boat that sinks underway, four boats sink in their slips.
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.
It is also interesting to note that the finger was pointed at fittings above the waterline in 9% of the sinking claims.
Water falling from the sky, either rain, snow, or sleet, accounts for 32% of sinking claims.

[thinwater]

In the north country snow load can push boats down by 2-6 inches, changing above WL to below WL. Combined with bad exhaust hoses, that sinks boats every years. Also ice-clogged drains.

[Cadence]

Originally Posted by GordMay

Remember: At sea, a boat is [almost ] always manned, whereas dockside it's mostly unattended.

More than two-thirds of the reasons why boats sank could be considered preventable. Half of those preventable claims, or one-third of the total, involved boats that sank due to the gradual failure of a part below the waterline.
And, according to BoatUS records, for every boat that sinks underway, four boats sink in their slips.
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.
It is also interesting to note that the finger was pointed at fittings above the waterline in 9% of the sinking claims.
Water falling from the sky, either rain, snow, or sleet, accounts for 32% of sinking claims.

That 32% is an interesting figure. I can't imagine that, was there additional explanation? I can see it with an open skiff.

[GordMay]

Originally Posted by Cadence

That 32% is an interesting figure. I can't imagine that, was there additional explanation? I can see it with an open skiff.

Blocked (leaves & debris, and closed thru-hulls) cockpit drains/scuppers.

[Cadence]

Originally Posted by GordMay

Blocked (leaves & debris, and closed thru-hulls) cockpit drains/scuppers.

Thanks! It still seems a high %, maybe I just haven't noticed other peoples habits or choices of boats?

[waterman46]

Originally Posted by zeehag

for this reason hoses from inside of boat to outside of boat with above water thru hulls have a riser made of that hose which rises to deck level before heading thru hull. ... you donot want any valves on a bilge pump hose when it comes to pumping as those fail and no pumping happens.

A riser made of that hose would not have helped. OP wrote that hose was found disconnected from the thru hull fitting.

[leftbrainstuff]

No risers? Bilge pump discharges are above the water line and clearly need to be open.

[stillbuilding]

Just for fun i will throw in a recent event with my 60’ yacht.

I have three 2” bilge exits about 12” above the waterline.

Tied up to a concrete wharf for few months work alongside. All good until i temporarily adjusted a stern line which allowed the stern to swing out, the bow to swing in and the bulwark caught under the wharf. Not noticed before i drove off to support the local chandlery.

The yacht was about 30 degrees over before some astute locals noticed and imaginatively disengaged the yacht with a forklift and lines. Big tidal range obviously.

Now the funny thing is that the day before this event i had fitted ball valves to the 2” bilge outlets and had them closed.

The bilge exits were well under water for this event and i reckon the damage may have been considerably greater if the valves had been open or not fitted. Perhaps partial flooding may have disengaged the bulwarks. Or perhaps the three 2” discharge lines would have given a total loss.

Not sure if this changes any conclusions. Probably the exception which proves the rule.
No rule to suit all circumstances hey.

[stillbuilding]

Yep, just found the damaged bulwark hiding under the Bruce anchor.[ATTACH]182808

[kmacdonald]

Originally Posted by GordMay

Blocked (leaves & debris, and closed thru-hulls) cockpit drains/scuppers.

A good reason to get rid of seacocks in drain lines. Looks like they sink more boats than they save.

[BadnBlonde]

Interesting post. I was cleaning out a sink drain a few weeks ago and thought it was silly that all the above waterline thru-hole drains had valves. Not so silly!

[argonauta1]

In most boats, should the exhaust hose disconnect within the engine area, the siphon loop should prevent flooding. No loop? Better install one. Yes, most vessels have through hulls above the water line usually from a fridge exhaust for cooling water or a brine exit from a desalinator. Also, a shower outlet is usually above water. Good thing to check as most do not have a shut off.