Not directly a model boat link, buta lot of us use these on our models, so if you want a ridiculously low priced source of LED's in all sizes, colours, and even flashing look on ebay for a seller called amigoofchina, he's based in Hong Kong but gives an excellent service, and does packs in various (large) amounts,and ALWAYS includes free resistors, one per LED to allow them to be run from a 12v source. cost per light is dead cheap.
cost shipping total per LED
eg, 100 x 5mm White Flash 5000 mcd LED Bulb inc Free Resistors 12.99 3.50 16.49 16.5 pence !
50 x 3mm Blue Flash LED Light Alarm with Free Resistors 4.99 2.00 6.99 7 pence
50 x 3mm Green 5000 mcd LED Bulb with Lamp Free Resistors 2.99 2.00 4.99 5 pence
I and a few of our club members have used him several times, and a feedback of over 3500 speaks for itself ( if you know ebay).
try this link to his ebay shop if you are interested, I have no connection ( Hong Kong is a long way ) other that as a very happy customer
http://stores.ebay.co.uk/Amigo-Of-Chinajust as a for instance, I have fitted 4 of the 3mm blue flashing LED's into the roof of a Cararama 1:72 scale Coastguard Land Rover, and two in the roof light bar of the 1:72 scale RNLI Range Rover, along with 2 x 3mm white ones in the headlights, and they look great.
Regards
Aston