Given that we spend nearly the entire trip on the boat, there’s no point in bringing too much for nothing especially since airline baggage restrictions are more and more strict. Take suitable clothing for the actual trip and something to wear when visiting the islands or in Malé (for the return trip).
You may want to consider a windbreaker or light pullover for evenings in April and October.
Choose footwear with which you can walk in the water. Once on the boat, shoes leave the feet permanently but if you insist on clothing your feet or protecting them during a shower without damaging the boat, a pair of tongs will do (in any case, shoes prohibited in the wardroom). Taking into account the warm and dry weather, bring along light clothing, keeping in mind that most of the time is spent in a swimsuit. A sweatshirt or light jacket might come in handy for cooler evenings and a windbreaker in the case of rain.
If you want to bring a nice outfit for the evening, feel free, no one will mind, but it is not really common practice. In all cases, bring a pareu or beach towel, sunglasses and sunscreens with a high sun protection factor, sunhat or cap. For swimming: swimsuit, flipper, mask and (quality) snorkel, and a shorty or a light 3mm full wetsuit for diving. The boat is equipped with many 220V outlets for electronic apparatuses: cell phones, laptops, cameras and video camera, etc… don’t forget your rechargers!
Remember! You can not carry liquids in your hand luggage, nor creams or sharp objects: they will be siezed at customs. The same goes for alcohol and pornographic magazines…