Chris
The best diving in November to March although I did dive in sept but the vis and weather can be a little changable. The beaches are better in the south not so many beach boys. I dived in the North of Mombasa with Buccaneer Divers on Bambori beach, they are great and have their own wed site. I have also met an ex instructor from Dhani (sth Mombasa) and I belive pipi pila is a dive company down south - hope this helps

thanks for the reply. it is very helpful, cheers, chris.

http://www.pillipipa.com/guestbook.htm website for pilli pipa. We went to the south coast, Diani beach because it is supposed to be lovely, it was, but beach boys are a pain in the neck. Friendly, but forget going for a quiet stroll on the beach.

http://www.dianibeach.com/map/index.htm shows hotels there. We stayed in Leopard Beach Resort after our safari. Upgraded to a superior room and it was very nice (although we rejected our first room - shabby and not refurbished as we'd thought they all had been). I've seen disappointing reviews for the standard rooms. Hubby got a bad tummy twice but I was fine (first time he hadn't eaten in the hotel so don't think we can blame them).

A family of 8 stayed at Diani Sea Resort and all were quite ill on and off throughout their 7 nights there and said the hotel wasn't 'all that'.

Local opinion was that Diani Reef was the nicest in the area (probably the dearest).

http://www.tripadvisor.com/ShowForum-g294206-i9216-Kenya.html might suggest more options.

Can't comment on the nightlife at Diani - we were knackered by 10pm (golden oldies!), but Forty Thieves bar is supposed to be good (?).

There are lots of hotels to choose from in the South Coast. Depends on what you prefer and your budget. The Leopard beach hotel is very nice with good food and facilities. On the other hand you have smaller and more intimate places like Diani house and the Cove treehouses...
Having stayed at both the North and South, I definitely prefer the latter! The beach is much cleaner and less crowded and overall a lovely experience! If you prefer a beach holiday with a bit more culture involved then why not try Lamu Island?