In Maldives nudism and topless sunbathing are not allowed anywhere, including on resort islands. You should be sensitive to local dress standards especialy when visiting non-resort islands. Diving and snorkelling here is a the best thing. Make sure you get proper instruction, and watch out for the sharks and also to other dangerous things such as sea urchin or touch a lionfish. Ok, they don’t jump out at you and attack, just don’t touch them. About dangerous fish be watchful to stonefish which is camuflaged close the stones. Take care where you put your feet when snorkelling, swimming or scuba diving amongst coral reefs.