It depends where on the island you will be Rebecca. I have dived there quite a lot, mostly for commercial work, but done a bit of recreational diving as well.
Although its a small Island, there are quite a few differant areas for diving and unless you intend hiring a car travel by the local transportation system is a bit of a hit and miss affair - if you do use it, throw away your watch - it dosnt work in Mauritius.!
Anyway, I will assume its Grand Bay as this is the most popular tourist area and definately the best diving area.
All of the big hotels have affiliations to dive operators, getting into the water is no problem, just enquire at reception. There are also a few operators who just sort of sign you on from the beach, its quite acceptable but I found the operators with hotel affiliation to be somewhat more professional.
The diving is typically close to shore so dont expect long boat rides, shore diving is a waste of time, in my opinion dont even bother. Some of the more interesting sites I dived were Black Forest and Coral gardens, both are reletively deep, around 35 metres and 25 metres respectively, but I found the shallow dives boring and the reefs in poor condition.
Diving is fairly expensive in Mauritius, ranging from around 40.00 to 60.00 Euros for a single tank dive (depending on location and season) - Try and do the deeper reefs and I would avoid the wrecks, they are usually small fishing boats dropped in a sea of sand, I swam around the one I visited in 5 minutes and was bored to tears in 10.
Hope this helps, have fun, its a great little Island to visit and you will be there in peak summer - take lots of sunscreen.!
