I just came back from a 13 days trip to Mauritius.
During our stay we wanted to go on few excursions. We planned to go on diving safari, a catamaran cruise to gabriel island, go on the submarine trip, and to find some additional excursions upon our arrival to Mauritius.

From my experience, after doing a serious market research, and of course after booking and going on the excursions, I can recommend to book these excursions on Mauritius Attractions website - http://www.mauritiusattractions.com.

They offer a very big selection of excursions and tours, it was easy to order all the excursions we were looking for, and their rates are very good - far better then with any other tour agency we found while in Mauritius (we stayed in Grand Baie).

I can also inform you that while we were in Mauritius we booked few other excursions (south-east tour, hiking trip and swimming with dolphin boat trip) through the hotel we stayed in, but later when, we arrived back home we found that the hotel really over charge us for these attractions and that you can find them for about 100% less on that website.

I hope this helps.