Wetsuits work by trapping a thin layer of water next to your skin and come in a range of thicknesses, choose one which is snug but not too tight. 7mm wetsuits are ideal for cold water, modern 5mm wetsuits are ideal for the Red Sea and 3mm wetsuits or less are ideal for the tropics. See our wetsuit kit advice pages for more information on selecting a wetsuit, also have a read about neoprene and the features you need to look for in a wetsuit. The first thing you must decide is which thickness of wetsuit is best for you. Generally, we would always recommend going for a thicker wet suit rather than a thinner wet suit if you are unsure. It is unlikely that in the water you will become too hot. In tropical waters consider a full-length wetsuit to protect your arms and legs from abrasion and the resulting stings. The time when you are most likely to overheat in a wetsuit is waiting to enter the water, so try to leave suiting up until last and drink plenty of water. Remember if you plan on deeper diving the water temperature will get colder as you get deeper. There may be several layers of water temperatures, so plan your wetsuit around the deepest part of your dive. In colder waters you may want to consider layering your thermal protection in addition to your main wetsuit. Just adding a rash vest under your wetsuit as a base layer will keep you much warmer than without. This is also a great tip if you have an old wetsuit that has compressed over the years and is no longer as warm as it once was to boost its warmth once again. If you recall from your dive training, as you descend deeper the neoprene which the wetsuit is made of will crush and compress, this means that the wetsuit will become less buoyant so you will need to add air to your BCD to remain neutrally buoyant. After the day or nights diving wash your wetsuit in fresh water and allow it to dry in the shade. Avoid leaving your wet suit neoprene exposed to direct sunlight for long periods as it degrades the neoprene.