Hi Carina
We're going to the Renaissance for a week in May, so I know a bit about it! Also, we have a trip report on site from Alan Ewart, one of the UK Correspondents who spent Christmas there. Apparently it is a fab place - very large rooms, gorgeous bathrooms.
Right, to answer your questions: There is a dive centre at the hotel. It is run by Dive In and their website is <a href="http://www.divein.it/eng/divein.htm" >http://www.divein.it/eng/divein.htm</a> You can do shore dives on the house reef - they have a long jetty built out over the top of the reef table to the drop off. They also run boat dives to all the usual spots - prices are much the same as anyone else and you can buy dive packs.
The hotel iteself is in the Ras Umm Sid area of Sharm which is on a headland outside of Naama Bay, the resort centre. It is very easy to get cabs down into town for shopping and all the restaurants.
Ras Mohammed is about an hour or sos steam away by boat. Lots of day trips are run there and you shouldn't miss it. All the depart from the harbours down in Sharm and the dive shops send a van to pick you up. One advantage of using the hotel's operator is that they will take you straight to the boat instead of going all round the other hotels doing pick up. They generally offer 2 tank boat dives and most offer a very good lunch on the boat for a couple of pounds. Some will take non divers as passengers and a boat trip to Ras Mo is a nice day out - see the shoreline etc.
You don't mention your diving experience, so forgive me if I am teaching my grandmother to suck eggs with what follows!!! The diving at Ras Mo is generally not difficult. However, especially in the summer when you are going there can be strong currents at Shark Reef (the main site there)so you should have some experience of diving in current ie don't fight against it if it is too strong, if there is a light current go against it first and then turn back for the return, if you need to cross a plateau against a current, swim diagonally to the force of the current rather than head on. If you have to surface and the current is running, surface against the reef wall as it will give you some shelter and a point of reference, try to avoid going out into the blue. To put it in perspective, I've dived there many times and only hit very strong current on three occasions and the dives were still great.
The dives there are spectacular wall dives so you need to watch your depth and buoyancy because it is very easy to drop down through the water if you don't concentrate. It is very clear and there is very little loss of light even down to 50+metres. The surface conditions are generally very light so don't worry about that. Generally speaking a reputable operator will recognise that there is a current - put you in to account for it, warn you in the brief and also deploy a line off the back of the boat for you to grab hold of. You can dive it at almost whatever depth suits you and you can use the wall to do a multilevel. So for instance, drop in on the wall to 30m, swim along at that depth for a while, come up to 20 and go on, reach the plateau and come up to that and then tootle about in the shallows at the end. Most sites in Sharm are like that - the reef comes up almost to the surface so you don't have to go into blue water.
I would recommend the following sites: Ras Mohammed (any of the sites), Jackson Reef, Gordon Reef, Thomas Reef, Ras Nasrani, The Alternatives, the Dunraven, Thistlegorn (currents can be wicked here though so watch out). The dives immediately around Sharm used to be utterly fab but are a bit dived out now - too many day boats. Having said that, they are still very pretty - I like Ras Nasrani and Ras Umm Sid (where the hotel is) and for shore diving and for night diving would take a lot of beating. If this is your first time to the Red Sea you will probably think they are brilliant until you get to Ras Mohammed or the outer reefs like Gordon.
Have a look at our Sharm trip reports on the Trip Reports page - we have quite a few and of course one on the Renaissance. Let me know if I can help you further.
Allie