phasmatis wrote:
A friend of mine has a Beneteau 345 moored in Corfu, it was due to be
lifted out for the winter this morning but unfortunately he had a phone
call from the Marina to say his boat had sank! The boat was stern on to
the pontoon and it was only the ropes holding the stern end out of the
water. There are no other boats on the pontoon as they have already
been lifted out.

The boat has now been pumped out and is afloat again and on inspection
there is no obvious reason why the boat would take on so much water to
sink the boat in a 12 hour period since it was last viewed.

The evening before the boat sank a large power craft powered at speed
through the Marina and created a very large bow wave, the only
explanation as to the cause that has been offered is that the bow wave
caused the toilet to overflow and created a syphoning effect which in
turn filled the yacht with water.

Anyone heard of this before?

Yup, my cousins bilge pump started syphoning and sank his boat.

In Gtpnf.94832$ki.57113@pd7tw2no Gary writes:

phasmatis wrote:
A friend of mine has a Beneteau 345 moored in Corfu, it was due to be
lifted out for the winter this morning but unfortunately he had a phone
call from the Marina to say his boat had sank! The boat was stern on to
the pontoon and it was only the ropes holding the stern end out of the
water. There are no other boats on the pontoon as they have already
been lifted out.

The boat has now been pumped out and is afloat again and on inspection
there is no obvious reason why the boat would take on so much water to
sink the boat in a 12 hour period since it was last viewed.

The evening before the boat sank a large power craft powered at speed
through the Marina and created a very large bow wave, the only
explanation as to the cause that has been offered is that the bow wave
caused the toilet to overflow and created a syphoning effect which in
turn filled the yacht with water.

Anyone heard of this before?

Yup, my cousins bilge pump started syphoning and sank his boat.

My neighbour in the club marina had a 30 footer, where the builder was
being smart and had joined the bilge pump and kitchen sink outlet. If
you left the kitchen sink plug on after you had pumped the bilge, you
had a perfect siphon. Of course it happened once. He was lucky that
someone noticed that hes freeboard (usually about six inches higher than
mine, was about a foot lower than mine and came to the rescue.

Another case was with the toalet pump in another boat. So if you make a
sifon, once it will work. Just wait long enough.

- Lauri Tarkkonen

Lauri Tarkkonen wrote:
My neighbour in the club marina had a 30 footer, where the builder was
being smart and had joined the bilge pump and kitchen sink outlet. If
you left the kitchen sink plug on after you had pumped the bilge, you
had a perfect siphon.

You're saying that bilge pump discharged BELOW the waterline???? What
WAS the builder thinking??? Otoh, I had a consulting job last year on a
70' trawler on which both the gray water and the black water tank vents
terminated in charcoal canisters in the engine room, right next to a
propane furnace. So anything is possible.

Of course it happened once. He was lucky that
someone noticed that hes freeboard (usually about six inches higher than
mine, was about a foot lower than mine and came to the rescue.

Another case was with the toalet pump in another boat. So if you make a
sifon, once it will work. Just wait long enough.

But you CAN'T create a siphon if you close the bloomin' seacock! No
matter how inaccessible and inconvenient that may be, it's a whole LOT
easier and more convenient than drying out your boat after it's sunk in
its slip.
--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Gary wrote:
Yup, my cousins bilge pump started syphoning and sank his boat.

I don' TEEENK that's what happened...for a couple of reasons: bilge
pumps don't bring water INTO the boat, they remove water FROM the
boat...and the thru-hulls for bilge pumps are above the waterline. So
unless there was already enough water in the boat to put the bilge pump
thru-hull under water, there's no way that a siphon can start in a bilge
pump line.

The water that sank your cousin's boat had to be coming in somewhere
else...and either the bilge pumps clogged and failed, or they kept
pumping till they drained the batteries and died...allowing the boat to
fill up and sink. Or, the water was coming in faster than the bilge
pumps could keep up with it. Or any combination/all of the above.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Peggie,

Trying to tell people to install vented loops is like trying to get them to
close seacocks when they leave the boat for extended periods. Ain't gonna
happen.

When you tell people they should close all the through hulls prior to
leaving they say that is not what they are for, or that would take to long,
or don't you trust your hoses, or I can't get too my through hulls,,,,and
that is why most boats sink at the dock.

You should see the looks I get from the yard when I tell them the ignition
key is hanging on the closed raw water engine intake and they will need to
open the intake when getting the key to start the engine.

B

"Peggie Hall" wrote in message
...
Gary wrote:
Yup, my cousins bilge pump started syphoning and sank his boat.

I don' TEEENK that's what happened...for a couple of reasons: bilge pumps
don't bring water INTO the boat, they remove water FROM the boat...and the
thru-hulls for bilge pumps are above the waterline. So unless there was
already enough water in the boat to put the bilge pump thru-hull under
water, there's no way that a siphon can start in a bilge pump line.

The water that sank your cousin's boat had to be coming in somewhere
else...and either the bilge pumps clogged and failed, or they kept pumping
till they drained the batteries and died...allowing the boat to fill up
and sink. Or, the water was coming in faster than the bilge pumps could
keep up with it. Or any combination/all of the above.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Bryan wrote:
Trying to tell people to install vented loops is like trying to get them to
close seacocks when they leave the boat for extended periods. Ain't gonna
happen.


Yep. And that's why somany boats are in the shape they're in.


When you tell people they should close all the through hulls prior to
leaving they say that is not what they are for, or that would take to long,
or don't you trust your hoses, or I can't get too my through hulls,,,,and
that is why most boats sink at the dock.


Yep again. "That's not what they're for"??!? Gee what are
they for then?

"Can't get to my thru-hulls"?!?!!?!!!???!! Why did you buy a
freekin' boat with inaccessible thru-hulls?

Another common one is people who don't know where their
thru-hulls are.


You should see the looks I get from the yard when I tell them the ignition
key is hanging on the closed raw water engine intake and they will need to
open the intake when getting the key to start the engine.


Another goody is people not closing their fuel tank valves.



Gary wrote:
Yup, my cousins bilge pump started syphoning and sank his boat.

"Peggie Hall" wrote
I don' TEEENK that's what happened...for a couple of reasons: bilge pumps
don't bring water INTO the boat, they remove water FROM the boat...and the
thru-hulls for bilge pumps are above the waterline.

Umm, not all of them are.


The water that sank your cousin's boat had to be coming in somewhere
else...and either the bilge pumps clogged and failed, or they kept pumping
till they drained the batteries and died...allowing the boat to fill up
and sink. Or, the water was coming in faster than the bilge pumps could
keep up with it. Or any combination/all of the above.


Rainwater can do it. Also if shore water supply is left
hooked up, and a leak begins (or a hose blows out); that is
a very common way boats sink at the dock (accoring to
insurance). I guess leaving shore water hooked up goes on
the list with leaving thru-hulls & fuel valves open....

Fresh Breezes- Doug King

DSK wrote:
Bryan wrote:

Trying to tell people to install vented loops is like trying to get
them to close seacocks when they leave the boat for extended periods.
Ain't gonna happen.


Yep. And that's why somany boats are in the shape they're in.


When you tell people they should close all the through hulls prior to
leaving they say that is not what they are for, or that would take to
long, or don't you trust your hoses, or I can't get too my through
hulls,,,,and that is why most boats sink at the dock.


Yep again. "That's not what they're for"??!? Gee what are they for then?

"Can't get to my thru-hulls"?!?!!?!!!???!! Why did you buy a freekin'
boat with inaccessible thru-hulls?

Another common one is people who don't know where their thru-hulls are.


You should see the looks I get from the yard when I tell them the
ignition key is hanging on the closed raw water engine intake and they
will need to open the intake when getting the key to start the engine.


Another goody is people not closing their fuel tank valves.



Gary wrote:

Yup, my cousins bilge pump started syphoning and sank his boat.


"Peggie Hall" wrote

I don' TEEENK that's what happened...for a couple of reasons: bilge
pumps don't bring water INTO the boat, they remove water FROM the
boat...and the thru-hulls for bilge pumps are above the waterline.


Umm, not all of them are.


The water that sank your cousin's boat had to be coming in somewhere
else...and either the bilge pumps clogged and failed, or they kept
pumping till they drained the batteries and died...allowing the boat
to fill up and sink. Or, the water was coming in faster than the
bilge pumps could keep up with it. Or any combination/all of the above.


Rainwater can do it. Also if shore water supply is left hooked up, and a
leak begins (or a hose blows out); that is a very common way boats sink
at the dock (accoring to insurance). I guess leaving shore water hooked
up goes on the list with leaving thru-hulls & fuel valves open....

Fresh Breezes- Doug King

I didn't conduct an investigation. His boat sank, it had a bilge pump,
no head, and an outboard. The only thru hull was the bilge pump outlet.
It's his story. Argue about something else.

Rainwater can do it. Also if shore water supply is left hooked up, and
a leak begins (or a hose blows out); that is a very common way boats
sink at the dock (accoring to insurance).



Gary wrote:
I didn't conduct an investigation. His boat sank, it had a bilge pump,
no head, and an outboard. The only thru hull was the bilge pump outlet.
It's his story. Argue about something else.

Aw, c'mon. Anyway, it wasn't me insisting that it couldn't
be the bilge pump.

DSK

Bryan wrote:

Trying to tell people to install vented loops is like trying to get them to
close seacocks when they leave the boat for extended periods. Ain't gonna
happen.

I know. Today's typical boat owner is a new breed...clueless, happy to
remain so, unwilling to learn even the most basic skills, do any manual
labor, or take any responsibility for ensuring the safety of his own
boat...if I've heard "that's why I have insurance" once, I've heard it
100 times! Perhaps if the insurance industry stopped paying claims for
preventable losses.... But that ain't gonna happen either.

Btw, Doug... Not all bilge pump thru-hulls are above the waterline???
That's nutsy design...how can a pump empty out a boat through a hole
through which water can come in faster than the pump can push it out???
Otoh, I just learned that a lot of cockpit drain through-hulls are
also below the waterline...which makes no sense to me either...sigh...




--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304

Bryan wrote:
Trying to tell people to install vented loops is like trying to get
them to close seacocks when they leave the boat for extended periods.
Ain't gonna happen.


Peggie Hall wrote:
I know. Today's typical boat owner is a new breed...

I dunno if it's so much a "new" breed as the same old
dumb-ass from all ages of history, only set free in today's
consumer-driven easy-credit economy.

Would we have it be any different, truly? Then it would be
much more difficult to be above average!

... clueless, happy to
remain so, unwilling to learn even the most basic skills, do any manual
labor, or take any responsibility for ensuring the safety of his own
boat...

Careful, now you're swerving into politics!

... if I've heard "that's why I have insurance" once, I've heard it
100 times! Perhaps if the insurance industry stopped paying claims for
preventable losses.... But that ain't gonna happen either.


That's true but many insurance companies either raise rates
on "accident" prone boaters just like they do for similarly
inclined auto drivers; and also insurance companies quit
writing boat policies. A big wave occurred after Hurricane
Katrina, and boat insurance is going up.

All the above are among the reasons why I think the
recreational boating market is not going to climb up into a
seller's market any time soon, if ever. The impact of peak
oil on the macro economy and the reduced interest in outdoor
activities on the part of young people (most of whom would
be perfectly content to sit around playing video games) are
two more.

Btw, Doug... Not all bilge pump thru-hulls are above the waterline???
That's nutsy design...how can a pump empty out a boat through a hole
through which water can come in faster than the pump can push it out???
Otoh, I just learned that a lot of cockpit drain through-hulls are also
below the waterline...which makes no sense to me either...sigh...


Well, boat design & construction is a compromise. Some
compromises are better than others

DSK