A family-run resort, True Blue Bay puts an emphasis on activities. These include rum-tasting sessions with a vague pretence at being educational, yoga classes, kayaking and tango lessons. But the weirdest of the lot is the chance to be a mermaid (or merman – it’s not sexist). This involves being given a special tail to slip over your legs and having to get around the swimming pool using a freakish version of the butterfly stroke