Not only the chance of losing it but some lakes I know don't allow them. My old syndicate lake for example, if you were caught with one or anything similar you would get banned. As the ranger said, they're for noddy's. Also if you rely on such a gadget and you do go onto a lake that does not allow them then I'd say you will be at a major disadvantage by the boy's that know and have learnt their watercraft.
Without a doubt my watercraft knowledge is my biggest asset. Watercraft is more than just seeing a fish show or finding fish. Its what the fish do on certain winds, certain air pressures, times of the year, amongst other things etc etc etc. I've had countless occasions where I've fished a totally different part of the lake to the majority of anglers on the lake on that day and caught when most of the rest have failed all because I've seen something they haven't or worked out where they will be. If a carp doesn't show then most anglers I'd say are stumped on where they are but there are lots of other signs to look for which not even a deeper will show you anyway. Learn these things and you'll catch more, simple.