Years ago, we had a near sinking on one of our test boats due to a failed 0-ring on the speed sensor through-hull installed by a previous owner. The sinking would be attributed to the failure of an O-ring, and because the sinking was consequential to the failure of a maintenance item and we did not have consequential loss coverage, the insurance would not have paid the claim. In fact, most boats sink at the dock due to failure of some minor item, and most policies don't cover the damage consequential to the failure of that item. In other words, we are sailing bare, without insurance coverage for our most serious exposure.
We think the best bet is the modern keel/centerboard. Unlike centerboards of 20 years ago, the new ones are very efficient going to windward with the boards down and not all that bad with the boards partially raised or withdrawn into a stub keel.