For diving in Hawaii, a 3mm full wetsuit is typically ideal. The waters around Hawaii are warm, averaging between 75–80°F (24–27°C) throughout the year, so a thicker wetsuit isn’t usually necessary. Here are some factors to consider when choosing the right wetsuit:

1. Thickness: A 3mm wetsuit provides enough warmth for most divers, balancing comfort and flexibility. If you tend to get cold easily, you might want to bring a 5mm suit, especially if you’re diving deeper or during the winter months when water temperatures can be slightly cooler.

2. Full-Length vs. Shorty: A full-length wetsuit offers better protection from potential scrapes, stings, or jellyfish encounters. However, some divers find a shorty wetsuit (covering only the torso and upper limbs) to be comfortable in Hawaii’s warm waters, particularly for shallow dives or if they don’t get cold easily.

3. Fit and Comfort: Choose a wetsuit that fits snugly but allows for easy movement, as an ill-fitting wetsuit can make for an uncomfortable dive.

4. Type of Diving: For deeper or multiple dives in a single day, a 3mm full wetsuit is best to keep warm over extended periods. If you’re snorkeling or doing a single shallow dive, you might find a shorty or thinner wetsuit more comfortable.

Overall, a well-fitted 3mm full wetsuit is the most versatile choice for diving in Hawaii’s warm waters, offering comfort, warmth, and protection.