Most resorts in Raja Ampat conduct scuba-diving activities year-round; the vibrant coral reefs remain an exquisite spectacle in all weather. However many liveaboard operators spend midyear in other parts of Indonesia, and some resorts close for several months due to stronger winds.
Visibility tends to be clearer in these months (May to September); however October to April are generally considered an optimal time to visit Raja Ampat due to increased plankton concentration, which attracts pelagic species such as manta rays.
Visitors are advised to be aware of strong currents throughout the area; many sites are best suited to only advanced and experienced divers. There are however, a great deal of protected and sheltered fringing reefs, and introductory diving and snorkelling can be enjoyed along these at any time of tide.
Water temperature does not vary greatly throughout the year, remaining at around 28°C /83°F.
Most divers find a long three mm wetsuit sufficient, although some people prefer five mm suits. It should be noted that most reputable operators do not allow the use of dive gloves.
Some resorts and liveaboards provide reef hooks to be used on drift dives in strong current; all reputable dive operators will provide SMBs and other signalling devices for rent, requiring all divers to have these on their person.
Most resorts rent high-quality and well-maintained snorkelling equipment, although it is advisable to contact the operation and reserve these in advance. Some homestays and villages hire masks and fins, but visitors are recommended to check the function and quality of these items before renting.