Small Boats:

Go Sail          http://www.go-sail.co.uk/ownersclubs.asp

Privateer 20 site (sister boat to Shipmates!)
                http://uk.groups.yahoo.com/group/privateer20

Cruising Association          www.cruising.org.uk/index.htm       

Dinghy Crusing Association                  www.dca.uk.com/

Traditional Boats                                www.tradboat.co.uk

Trail Sail Association                        www.trail-sail.org.uk/

Weather:

Accuweather                        http://www.accuweather.com/

XCweather                          http://www.xcweather.co.uk/   

Frank Singleton (superb site for sailors!)
                                            www.franksingleton.clara.net/


Met Office - weather                    www.met-office.gov.uk/

wetterzentrale - weather                www.wetterzentrale.de/
(charts etc)