Visit our Popular Forums

ssanzone · 25-09-2011, 13:18

this morning i watched 'the reef' (The Reef (2010) - IMDb).

typical shark movie... hysterical women, brave men in shark infested water getting picked off 1 at a time.

in this instance, the vessel sailed thru a reef and (of course) ripped off the keel which (of course) capsized the boat which (of course) resulted in 1 scared guy 'i fish these waters and know whats out there... i am staying here sitting on the capsized boat' and the other 4 stilling 10 miles to an island. i know i know... gripping, right?

and to my question... is it possible that a keel gets sheered off while running aground?

i suppose if a whale clipped the keel i could see losing the keel, but thru a reef or beaching her at 6knots +/-?

**boatman61** · 25-09-2011, 13:28

Yes...
Fin keel an 80% certainty....

**Jim Cate** · 25-09-2011, 13:36

Quote:

Originally Posted by boatman61

Yes...
Fin keel an 80% certainty....

Be serious, mate! I've run aground, arock, areef more times than I like to admit in three fin keeled boats, and have suffered no damage beyond some coral sticking into the lead.

You are showing signs of being foolishly prejudiced.

Cheers,

Jim

gpdno · 25-09-2011, 13:50

lol, saw the movie and have wondered about that myself. Some boat have that new fangled bulb keel. Mine has a big old lead incapsulated keel so it's not going anywhere.

Back in 2008 a sailboat from Texas A&M capsized in the Gulf of Mexico after loosing the keel. One of the six crew members died, so it does happen.

**boatman61** · 25-09-2011, 13:53

Quote:

Originally Posted by Jim Cate

Be serious, mate! I've run aground, arock, areef more times than I like to admit in three fin keeled boats, and have suffered no damage beyond some coral sticking into the lead.

You are showing signs of being foolishly prejudiced.

Cheers,

Jim

AGAINST LOSING MY KEEL.... yer darn tooting I am...

Know of one big J boat lost its keel on a sand bar in the Medway... going fast..
Known a few in the Solent/Poole area as well.... okay, some not completely but it happens...
He is talking 6+kts...
You were lucky your keel was lead... much more forgiving... and I doubt you were doing 6kts

**roverhi** · 25-09-2011, 13:57

If a keel is a bolt on, it's very possible the keel can be ripped off whether it's a fin or full keel boat. Not very likely with a full keel because of the long attachement area, however. An encapsulated keel, it's very unlikely as you'd have to destroy much of the boat to get the lead out.

There are fin keels and then there are fin keels. The modern ultra thin/short keels with a big bulb hanging off the bottom are very prone to leaving their lead littering the bottom. It's a matter of phyics. Tying to attach those very thin keels to the hull in a way that will guarantee that they won't fall off is difficult. It's just too small an area supporting something that's way heavy and subject to extreme stresses from practically all directions.

The older longer fin keels are structurally way easier to design a strong keel attachment. They will also tolerate a poorly designed/executed/deteriorated keel to hull attachment better.

ADMPRTR · 25-09-2011, 14:00

Quote:

Originally Posted by gpdno

Back in 2008 a sailboat from Texas A&M capsized in the Gulf of Mexico after loosing the keel. One of the six crew members died, so it does happen.

I understand that incident was the result of poor design and poor repair of previous damage from a grounding.

I would think the level of damage that could be expected in a underwater collision would be a combination of speed and the how quickly the depth disappears. If one hits on a shoal that gradually gets shallow, there would be less damage than a rock just a couple feet under the surface. In the former, the boat would grind to a stop but in the latter the boat would abruptly stop, with all the impact hitting at the keel joint. A shallow hit would not loose as much of the momentum by pivoting over the impact.

If you have poor design/poor repair/corrosion then you could loose your keel, IMO.

bob_77903 · 25-09-2011, 14:02

Quote:

Originally Posted by gpdno

lol, saw the movie and have wondered about that myself. Some boat have that new fangled bulb keel. Mine has a big old lead incapsulated keel so it's not going anywhere.

Back in 2008 a sailboat from Texas A&M capsized in the Gulf of Mexico after loosing the keel. One of the six crew members died, so it does happen.

The Texas A&M boat that capsized after losing it's keel had a faulty repair job done to the keel shortly before the loss. If you Google the boat you can get the whole history of the unfortunate event.

Rakuflames · 25-09-2011, 14:11

Quote:

Originally Posted by gpdno

lol, saw the movie and have wondered about that myself. Some boat have that new fangled bulb keel. Mine has a big old lead incapsulated keel so it's not going anywhere.

Back in 2008 a sailboat from Texas A&M capsized in the Gulf of Mexico after loosing the keel. One of the six crew members died, so it does happen.

Keels can come off if the bolts rust and fail. I looked at a boat once with a keel held on by eight bolts. Two were in pieces and the rest ready to go.

But that's not typical, and something more than running aground would be needed to take the keel off. Boats run aground every day.

**roverhi** · 25-09-2011, 14:18

The A&M boat keel repair was the result of a grounding. The hull to keel attachment was damaged enough on the grounding that the keel fell off after being subjected to the stresses of normal sailing a short while later.

zeta · 25-09-2011, 14:42

My fin keeled boat was shoved through 5 miles of southern Mississippi woods by Katrina and the keel was still attached but forward keel separated and ended up hanging about 3 inches below hull. No water in cabin, no holed hull but broken mast, imho Nonsuch 26 is a pretty tough hombre. Can't imagine the impact of completely ripping keel off.

barnakiel · 25-09-2011, 14:59

NO

1. the keel would rip out a huge portion of the bottom, not get 'sheared off',
2. at 6 knots the boat would simply stop and there would be damage, but no shearing off

PS If under sail she might lose the rig too.

b.

ssanzone · 25-09-2011, 15:10

is there a speed at which there is a risk of likely losing the keel?

i would think one is generally screwed by the hole left from the reef but, in my mind, upright and taking on water is better than capsized without a keel.

oddly, i dont consider the shark infested waters reason for worry.