I have dove there several times, the last time being last summer. The above water facilities are very nice (running water & flush toilets). They also have a nice dive shop with complete air & Nitrox fills. Just make sure your cylinders are up to date & correctly marked. Glen runs a very tight ship. I have seen their rescue plan in action & it is top notch. Underwater, the temps are comparable to Pennyroyal. Below 50- 60 ft it is about 40 degrees. The vis in the shallower waters during the summer is usually no more than 10- 15' (usually less). In the deeper water it is very dark because Mermet is smaller (surface area), but just as deep as Pennyroyal. The sheer walls blocks out a lot of the sun. A light is a good idea if going deep. They have nice docks for easy entry & exits. Their platforms are also very nice. There's lots to do & see. The 727 jet is really cool. If you go along the back wall at about 30 ft, be on the lookout for the paddlefish, very creepy & cool looking. Go ahead & check it out, it is worth it, even with poor vis.