Whilst their death is undoubtedly tragic, being "important" and "successful" make those lives no more valuable than any others. Last month, four people drowned attempting to cross the English Channel, but the same outpouring of grief and media attention wasn't splashed on them. Indeed, there are probably plenty of deeply unpleasant people who would be glad of their deaths.
The difference here, is that dying whilst larking about on a pleasure yacht is an avoidable death, whereas finding yourself in the situation where you are desperate enough to attempt a dangerous crossing in a small vessel that is almost certainly unseaworthy and overloaded is probably less so.
There seems to be a certain human tendency to elevate the super-rich to god-like personas, and then for those who are fortunate enough to find themselves in that group, by either luck of birth, luck of being in the right place at the right time, ruthlessness, skill, or a combination of the above, to start believing that they possess preternatural prowess themselves. Sadly, believing in your own indestructibility doesn't make it manifest, and being incredibly wealthy doesn't make the sea any less deadly or capricious.
My sympathies go out to the friends and relatives of all those who have died at sea, and I am led to wonder, if it is indeed true that the wealth of some individuals is due entirely to hard graft, whether inheritance tax on estates that are worth well over the amount that any dependants might need to live a reasonably comfortable life for the rest of their time on Earth, should be taxed at 100%. After all, if that money has been earned by merit, then logically, those standing to inherit it have not earned it by merit themselves. Either that, or we need to look again at why billionaires exist in the first place, and why the tax system doesn't prevent people trying to emulate the dragon Smaug. Having enough wealth to live comfortably, and to never have to work again is one thing, having so much money that it is noticeably otherwise missing from economic circulation is quite another.