How fast does a 28(39) boat SINK?-gctid376407

[Guest]

So in the technical thread I describe what happened however wondering as my engine compartment filled with water and the back of the boat started sinking ... How long did a guy really have??

[Guest]

Well I got a 28' boat, but I sure hope I never find out the answer to that question!, (knock on wood)

I really dont think there is a definitive answer. It all depends on the circumstances, for example, the rate of water the boat is taking on. If you have a 8inch diameter hole in the boat or a 15inch diameter hole obviously the 15inch hole will make the boat sink faster..

Lets just say prepare for the worse and hope it never happens.

[JimMc]

The table below shows various flow rates for different size holes 3 ft below water line.

SIZE	FLOW RATE GAL/HR	WEIGHT OF WATER/Hr	COMMENTS
1"	2,000	8 TONS	BROKEN THROUGH HULL FITTING?
2"	8,000	33 TONS	DEPTH SOUNDER TRANSDUCER?
4"	33,000	137 TONS	LAUNCH THE LIFE RAFT!

SIDE BAR INFORMATION FROM THE INSURANCE INDUSTRY:

1 For every one boat that sinks underway, four sink at the dock.

2 Failed through hull fittings account for 50% of all sunken boats.



This is why the typical 750 GPH pumps which in reality MIGHT pump 500 GPH are just not sufficient.

Also since a smaller boat has inherently less bouancy than a large boat having large pumps is even more important on a small boat.

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I have 6 bilge pumps on board.

The Scavenger pumps are too keep the bilges dry.

The Emergency Pump is for when the sheet really hits the fan.

My pumps smaller pumps run off one or the other starting battery. The Emergency pump runs off the House Bank.

• Forward Bilge Scavenger (Low Level)
  • 3 GPM Timer and Helm control ÔÇ£Scavenger PumpsÔÇØ
    • The timer runs the pump for 1 minute in the AM & PM

• Forward Bilge (Middle Level)
  • 750 GPH Float and Helm control ÔÇ£Fwd Bilge PumpÔÇØ

I have debated a large Emergency pump under the forward cabin but the only way a large inflow would occur would be the result of collision or holing the boat. In either case the damage would most likely be beyond bilge pump capabilities.

---------

• Mid cabin mechanical space bilge (Low Level)
  • 500 GPH Water Witch Solid State control only

---------

• Aft Bilge Scavenger (Low level)
  • 3 GPM Timer and Helm control ÔÇ£Scavenger PumpsÔÇØ
    • The timer runs the pump for 2 minutes in the AM & PM

• Aft bilge (Middle Level)
  • 1600 GPH Water Witch & Helm control ÔÇ£Aft Bilge PumpÔÇØ

• Aft bilge (High Level about 3" off the bottom.)
  • 3600 GPH Float Switch & Helm control ÔÇ£Emergency Bilge PumpÔÇØ

[Guest]

I can't speak with certainty, but I'm guessing a boat built in 1997 has sufficient amount of foam injection throughout to keep the boat at least partially afloat should the engine compartment fill with water. Am I correct?

For newer vessels, Coast Guard mandates require complete buoyancy for the entire hull, meaning the entire volume inside the hull can fill with water and the boat would still remain afloat.

[Guest]

Great info guys. 6 bilge pumps? wow - well doesnt sound as astonishing now as it may have prior to yesterdays experience. You must have had several of those put in. The water I was taking on was at a rapid rate. Something to look at.

Also had a suggestion that I should put in a high water alarm - that would have also been helpful.

I am just so thankful that shore was very close in sight that I was able to pull over and beach it immediately.

[yachtman]

Astral Blue wrote:
I can't speak with certainty, but I'm guessing a boat built in 1997 has sufficient amount of foam injection throughout to keep the boat at least partially afloat should the engine compartment fill with water. Am I correct?

For newer vessels, Coast Guard mandates require complete buoyancy for the entire hull, meaning the entire volume inside the hull can fill with water and the boat would still remain afloat.

That may be true for smaller boats IE.... waterski /open bow type boats. Larger cruisers have different requirements and I dont think they have to have flotation foam.

[Guest]

I posted a thread about a mid-20's boat sinking out of our home port a few years ago in less then 2 minutes. The crew was able to get off and were picked up by surrounding boaters but unfortunately the dog could not get out of the cabin and went down with the boat.

They made the big mistake of running a trolling bag off the stern. They took a large wave over the stern which filled up the engine compartment. They tried to accelerate forgetting that they were running the trolling bag, which pulled them further down. In less then a minute the stern got so heavy the bow popped straight up in the air, they fled the boat, another 30 seconds later the boat was gone. They have pics from the salvage with the boat sitting exactly as it looked when it went down.

This was less then 2 minutes from the time they took the wave till they were in the water.

The previous poster is correct that most larger boats do no contain any or enough foam to keep it afloat.

[Guest]

keithjabber wrote:
I posted a thread about a mid-20's boat sinking out of our home port a few years ago in less then 2 minutes. The crew was able to get off and were picked up by surrounding boaters but unfortunately the dog could not get out of the cabin and went down with the boat.

They made the big mistake of running a trolling bag off the stern. They took a large wave over the stern which filled up the engine compartment. They tried to accelerate forgetting that they were running the trolling bag, which pulled them further down. In less then a minute the stern got so heavy the bow popped straight up in the air, they fled the boat, another 30 seconds later the boat was gone. They have pics from the salvage with the boat sitting exactly as it looked when it went down.

This was less then 2 minutes from the time they took the wave till they were in the water.

The previous poster is correct that most larger boats do no contain any or enough foam to keep it afloat.

Wow how scary and humbling this was. As a boater you know the risks but you really don't think it could really happen until it starts. I feel even more thankful I was able to get to a shoreline.

Makes you wonder what type of safety kit/supplies do you prepare for in such a case.

[2850Bounty]

Impulse wrote:
So in the technical thread I describe what happened however wondering as my engine compartment filled with water and the back of the boat started sinking ... How long did a guy really have??

Man Wayne, that's tough to say. Ditto JimMc.... good info, BTW.

It has been commented on many times here that our main engine bay bilge pumps should be larger than what we think is needed.

I also know that many times we've discussed how simple and easy it is to install a bilge pump float switch buzzer or alarm, by paralleling in with the same bilge pump helm switch circuit.

Actually, Keith just mentioned this in your other thread.

Float turns on pump..... simultaneously turns on alarm.

Had a buzzer/alarm been installed... or even a warning light......, I'll bet that you would have looked sooner to see what was going on.

I know.... Hind Sight is always 20/20!

Astral Blue wrote:
I can't speak with certainty, but I'm guessing a boat built in 1997 has sufficient amount of foam injection throughout to keep the boat at least partially afloat should the engine compartment fill with water. Am I correct?

For newer vessels, Coast Guard mandates require complete buoyancy for the entire hull, meaning the entire volume inside the hull can fill with water and the boat would still remain afloat.

That would be interesting to learn.

I was thinking that the foam injection (or some type of buoyancy) was mandated for hulls under XX in length.... typically much smaller boats.

****************

Wayne, what's the latest on the cause of the leak?

Is the starter motor still working?

.

[Guest]

Impulse wrote:
Wow how scary and humbling this was. As a boater you know the risks but you really don't think it could really happen until it starts. I feel even more thankful I was able to get to a shoreline.

Makes you wonder what type of safety kit/supplies do you prepare for in such a case.

That depends on what kind of water you boat in. At a minimum I would keep a waterproof ditch bag within reach of the helm with handheld radio, water, food. If on water of any size I would also add epirb or plb (epirb if truly offshore).

PFD's should be within reach and not stowed away.

there are plenty of threads on this subject if you do a search.

[yachtman]

The following is part of the coastguard regs. when referring to length and type of boat required to have flotation any thing larger i believe is exempt from required floatarion........

§ 183.101 Applicability.

This subpart applies to monohull inboard boats, inboard/outdrive boats, and airboats less than 20 feet in length, except sailboats, canoes, kayaks, inflatable boats, submersibles, surface effect vessels, amphibious vessels, and raceboats.

[CGD 75-168, 42 FR 20243, Apr. 18, 1977, as amended by USCG-1999-5832, 64 FR 34716, June 29, 1999]

[SomeSailor]

A 2855 has no foam, but it has tons of flotation that would keep the bow sticking out at a minimum. Biggest danger when you get an engine bay full of water would be it running forward on the starboard side of that aft berth and then getting into the forward sides and causing the boat to go down by the stern and starboard side.

You probably know this, but you also had water all up in and around that aluminum tank, and in your starter and wiring. Hydraulic trim motor, gimbal bearing, and charger have all been wet. Your biggest problem (now that you've survived a sinking) is all of that corroding.

Your gimbal bearing is gonna be first... maybe the starter...

[yachtman]

SomeSailor wrote:
A 2855 has no foam, but it has tons of flotation that would keep the bow sticking out at a minimum. Biggest danger when you get an engine bay full of water would be it running forward on the starboard side of that aft berth and then getting into the forward sides and causing the boat to go down by the stern and starboard side.

You probably know this, but you also had water all up in and around that aluminum tank, and in your starter and wiring. Hydraulic trim motor, gimbal bearing, and charger have all been wet. Your biggest problem (now that you've survived a sinking) is all of that corroding.

Your gimbal bearing is gonna be first.....MAYBE THE STARTER.

I have never seen a starter that has been submerged salt or fresh water that lasted very much longer. Its days are numbered

[Guest]

Ok so the starter should be replaced regardless. Any other musts regardless of outcome on how they check out?

[Guest]

Anything electrical- moisture will creep along wireways and do all sorts of damage.