The Sea has been taking victims since Man first set foot into it and vessels upon it. It will continue to do so no matter what Man tries to do to mitigate those losses.
The problem with seeking a total coverage for every contingency is that it simply cannot be done.
The North Sea is much better covered now than it has ever been but we shall have those events that claim lives.
Prevention is the best method to minimize the losses.
SAR kicks in when the systems in place have failures.