What to .....
The Ultimate Model Forum - if its modelling .. its here!
A wide range of calculators.  
Of general interest.
A marvellous info source for colour mixing, equivalences and selection.  Highly recommended.
Marine Modelling International magazine
The wooden subchasers of WWII.  A great information source
John Lambert Plans site - a must visit for scratch builders !
John Drains PT Boat site - superb models & lots of build info.  Not to be missed !!
To Sail or not to Sail - easy to use weather forecasts
The site is aimed at technical and theoretical aspects of RC yacht racing. In particular, it has a number of spreadsheets to download. Although aimed at the IOM, they should be useful for any non-rotating fractional Bermuda sloop rig.
Want to know how a feathering paddle wheel works?  Here it is ...
US Vintage Model Yacht Group
US site for Thunder Tiger VICTORIA class yachts.  Great site and includes build and modification instructions.  Mail order for parts also.
Scale Model,Net:
British Military Powerboat Trust.  A great site for all things speedy.  Great info. source.
The Jubilee Sailing Trust web site.  For those into full size square rigger sailing, the trust offers crew cruising particularly for the disabled.  An interesting site and worth a visit.
The Model Hovercraft Association - great site for event listings.
Great source of information and a useful Forum on all hoverry things
Surface Warship Association
Scottish Fisheries Museum - Anstruther
New site specifically for Wee Nip class of yacht.  Created and run by our own Eddie Haig.
Well worth a visit ..........

Update: 7/4/13   19:22