if you remember to maintain your engine and put fuel in it, it is very unlikely to let you down.
'Very unlikely to fail' doesn't cut it in my book when there is no 'out' if it does let go. My experience (both first hand and observed in the experiences of other experienced pilots - all while flying over land, thankfully) is that even the best maintained engines in regular trouble-free use and with plenty of fuel correctly selected can and do (rarely, it's true) fail. But fail they can; be in no doubt of that.
A dingy might help. If you've room for one in the aircraft you fly.