Besides a double engine or tail rotor failure, you need to look at how short your sea crossings are. Don't forget that a minor issue over land of Fuel Transfer Pump failures can make you sweat over the sea if more than ~20mins from land (if fuel in the main tank isn't high enough to slosh over in the supply part).
At least with floats it does give you an option, albeit not the best one.
But, if it is a private flight, the choice is yours.