Totally untrue but some resorts are banning jetskis and/or quads - simply because there are too many and safety is an issue - I have seen drunken idiots going wild on jetskis and quads many times in Mozambique - an accident waiting to happen - the usual story - a few will mess it up for many.
You can't blame the authourities - these louts won't try it here in SA but think its ok there.
