As I discuss in another post, the conventional wisdom is that external
keels are better than internal keels. Statistics may show otherwise
but it is hard to tell. With the exception of that Woods Hole boat,
all the keel failures I could find involve external keels. Basically,
if your external keel fails, you die.
This just seems like bad engineering to me. You hang thousands of
pounds waaaaaaay down from a few bolts in a way that it is subject to
tremendous repeated changes in torque in a seriously corrosive
environment and you then bet your life on it? Uhhhhhhhhh, does this
make sense? Is anybody surprised at the deaths that have occurred
from these things?
Now, an encapsulated keel is supported over its entire surface via
glass cloth that is stronger than steel and does not corrode. Even in
the one case in Woods Hole where one was ruptured, the damage was such
that nobody died and it did not sink (or not fast enough to matter).
In my 28' internal keeled S2, I once hit a truck with my keel going 6
kts, yes, a truck. Following the so-called Storm of the Century, I was
motor sailing into Steinhatchee, FL when WHAM, we stopped dead with
the rigging shaking like crazy and we all fell over. I recovered mmy
balance and went below to check for damage and found none. A little
while later a coast guard boat came out and told us to watch out for a
truck that had washed out to sea in the storm, we told him we had
found it for him. I dove under her the next day and found the impact
area but there was no real damage.
Conventional wisdom is simply WRONG in this case.