"Chapeltown Divers"
BSAC 256 Sheffield (Chapeltown) Sub-Aqua Club

Links

Official site of the national British Sub Aqua Club
The Met Office - always check weather before launching or diving at sea.
UK Hydrographic Office
Admiralty EasyTide tidal predictions from the UK Hydrographic Office
Underwater Photography Magazine (www.uwpmag.com) - an excellent free online magazine published bi-monthly in .pdf format. Features articles on technique, kit, locations, marine life etc. Full list of backdated issues are on their download page. You will need Adobe Acrobat Reader 6.0 or later which can be downloaded here.
Maritime and Coastguard Agency. Especially relevant is the Boat Safety section of their "Sea Smart" sub-site.
Royal National Lifeboat Institution - the brave volunteers that come to our rescue if everything goes wrong. They accept online donations too.