Which is why I always keep my daggerboards extended just a bit further...

A friend of mine with a South African cat that had fixed keels ran over a deadhead last year. The keel pushed it down and it rebounded up directly into his saildrive leg. 6 months out of service, nearly catastrophic flooding and unable to get a replacement engine of the same size and horsepower, so now has different power port and stbd.

Frankly, with the shallow draft of my cat (other than the daggerboards of course), I find it pretty easy to stay in water deeper than 3' so it doesn't bother me. (And I have no desire to beach a 40'er)