when you moor them will you be switching off the radios
or will the radios still be switched on
if the radios are switched on you could make a large-ish lump of lead and attach it to the bow
take the boat out into the water dragging the lead then drag it back in and remove it when you
go to sail it. not much extra to carry and you don't need to keep too much of an eye on it as if it
was moored at the side there could be small wandering hands looking to it