This is absolutely must do on the Big Island, just how every review says. However, specifically Hang Loose Boat tours made the experience awesome. The big boat made us feel safe jetting out to the snorkel location at night, small chip bags, waters, and sprite were provided, and the crew was exceptional. Captain Bryce was the best! Made everyone laugh, made periodic announcements about how long it would be while we were headed out and headed in, and asked everyone throughout the snorkel experience if we needed anything or had questions. The manta rays seriously get close enough to brush up against you and are beautiful gentle giants to watch.