Floatation ??

Questions/concerns/issues. How did the other guy do it? Find out here.

Moderators: a j r, TDockside, Miles, Moderators

Post Reply
john
Posts: 261
Joined: Tue Dec 27, 2005 7:33 pm
Location: Crosby (Houston) Texas
Contact:

Floatation ??

Post by john »

Will a Thompson or Cruisers float or sink when capsized? No doubt if the engine and battery are removed, but with engine and battery will they??

Any trapped air would help for a while, maybe air trapped under deck, or air trapped in upside down hull.

Smaller hulls would be at greater risk, less wood (only floatation) and same size battery and engine weight to a degree.

Did Thompson or Cruiser's make a claim for flotation?

My 16' Cruiser's 202 has a listed weight of 650# for hull only without engine or battery. Since hull weight includes fastners, glass, and hardware, for a total none wood weight of 100?, lets guess at a wood weight of 550#. Most woods weighs about 31 pounds per cubic foot, so the hull should have about 275 pounds of "built in" wood floatation.

My 1960 75 Evinrude weights 225? and battery 75? total 300#. When submerged the engine and battery have very little "natural" floatation, but do have some.

Without trapped air, I have a very good possibility of sinking to bottom. At best it's got to be close.

Maybe the gas tank is empty, it would give 8 pounds of flotation for each empty gallon.

Better not carry an anchor or tool box.

Anyone can experience?

Should I add floatation? How and where?

If I start to sink, thrown every loose non buoyant item over the side, anchor with LONG rope attached, battery, tool box, ect!
a j r
Posts: 661
Joined: Sat Jan 07, 2006 3:09 pm

Post by a j r »

Are you having nightmares about sinkng?

"Natural floatation" was a term used very often by Thompson et.al. I suuposes this indicates the natural bouyancy of wood.

It's nothing I ever thought about and have no fears. I have used my wooden boats on Lake Michigan and Lake Superior. I have no qualms about doing so. I have been 16 miles from the mainland out into Lake Superior in my 57 Sea Lancer.

I personally wouldn't give it any thought.

Andreas
Last edited by a j r on Thu Nov 08, 2007 10:35 am, edited 1 time in total.
Image
john
Posts: 261
Joined: Tue Dec 27, 2005 7:33 pm
Location: Crosby (Houston) Texas
Contact:

Post by john »

No mightmares. Was helping a young neighbor replacce all the wood stringers, transom, and floor in a 1973 Glaston GT 150 and last night we put the foam floatation back in. Got me to thinking.

Floatation has got to be close.
John Hart
Posts: 208
Joined: Sun Jan 29, 2006 7:26 pm

Post by John Hart »

I have thought about this myself.... if something cracks bouncing across Green Bay, our heavy motors would probably drag things down pretty fast...

I was thinking about carrying a yellow raft, that inflates with a cartridge, but that would take half the boat to stow... AND costs and arm and a leg...

Too bad there isn't a 2 1/2 diameter, cartridge inflated 'beach ball' that you could keep under the bow... it might be the size of a gym bag, but fill with enough air to keep things near the surface....

John H.
john
Posts: 261
Joined: Tue Dec 27, 2005 7:33 pm
Location: Crosby (Houston) Texas
Contact:

Post by john »

For a 16' you would maybe need only 4 cubic ft of floatation. A 4" dia log of styrofoam would float 60# for every 8'.

I believe that I could fit 2 of these either side of my keel under the floor.. That would give 240# of extra floatation. They would not be fashened only held in place by the floor boards. You could also fashen foam under the front deck. I block 2' square and 3" thick would provide 60# of floatation.
txcaptdan
Posts: 348
Joined: Mon Jan 02, 2006 2:48 pm
Location: Weatherford, Texas
Contact:

Post by txcaptdan »

John,

When my 18' 370 Seacamper sunk from under me it stayed on the surface in a nose up attitude. I was at full speed and hit something that opened a scarf joint and peeled back a 24" opening in the garboard plank, to say the least she went down in less than 30 seconds. I had a 80hp Evinrude and a full compliment of rigging and equipment. She had no floatation beyond cushions in cabin and there were enough places for air to escape bow that it was not trapped air. I think the boyancy of the wood balanced out the weight of the engine.

She stayed afloat long enough to tow to the shallows and be patched and removed from lake within about 5 hrs. Wood floats! the boats I have seen sunk seem to swamp and stay near surface. She was repaired, engine dryed out and later that year won a Corinthian Award at Keels and Wheels for one of the top five in the show of 300+ entries.

A great reason to always wear your PFD when under way, I had only enough time to grab two life jackets that happened to be on the seat near by and my phone and walk into the lake. A complete story of sinking is on my web site http://groups.yahoo.com/group/classicoutboards/?m=0 under files.
Image
Dan Stober
1965 20' Cruisers Inc. 570 Seacamper
1962 20' Cruisers Inc. 502
1963 16' Cruisers Inc. 202 Seafarer
Weatherford, Texas
thegammas
Posts: 566
Joined: Sat Nov 25, 2006 2:10 pm
Location: Wilmington, Delaware. peterstransky@verizon.net - put wooden boat in the subject

Post by thegammas »

Dan - I finally got around to checking out the pictures on your yahoo site of when your king fisher sank - gave me a chill. I recall as a kid visiting my uncle who lives on the banks of the Pawcatuck river (forms the border between Connecticut and Rhode Island at the coast). There was a boat that looked very much like a king fisher (wasn't a lapstrake though). It was there every year for years and years and I never once saw it underway. Then one year we arrived for a visit, I went immediately to the river as I always did, and there she was, down at the stern, bow up just like in your one picture. It was still there when we left and I don't recall ever seeing it again.

Glad to see/hear your were able to rescue her. That was one heck of a hole.
Peter Stransky
1962 Cortland Custom Sea Lancer
Wilmington, Delaware
Post Reply