This dive site is located to the southeast of Sipadan. To get your bearing right, the only jetty in Sipadan is facing just about north. Access to Midreef is by boat for about 10 minutes from the main beach at Sipadan. Dive depth is between 15-20 metres. No noticeable current.
This dive site is regarded as one of the most colourful when it comes to the variety of soft and hard corals. Just as I descended to about 10 metres deep, there were already multitudes of coral variety that formed immaculate underwater gardens.
Anyway, this is probably not the place to see large pelagic, because I did see any. The hundreds of damselfish and colourful anthias (Pseudanthias sp.) did create underwater spectacles especially when combined with the coral reef scenes. Among the fish that I spotted were false clown anemonefish (Amphiprion ocellaris) hiding in a beautiful colony of green anemone, Moorish idols (Zanclus cornutus), sordid rubber-lips grunt (Plectorhinchus sordidus, somewhat scary-looking with that thick mouth), eastern triangular butterflyfish (Chaetodon baronessa), etc.
The collection of sea fan and soft corals was also very good to say the least. I spotted sea fans of Paracis sp. and Anella sp., cauliflower soft coral (Lemnalia sp.), variable bushy green feather of stars (Comanthina schlegelii), yellow fan coral of Villogorgia sp., crinoids of Comantheria briareus, feather of stars of Oxycomanthus sp., soft coral of Litophyton sp., etc.
Oh yes, there were about 3-4 green turtles here (Chlamydia mydas), most were barely noticing the engrossed eyes of the divers and busy grazing on the coral polyps.