Well I assume you are trying to light your model boat up on a 12v system and you know the voltage of the LED in question ?.
I recommend that you visit. www component -shop.co.uk. you will find the values of the different sizes you can get and how to wire them up correctly . and you can" Daisy chain" them provided you do not exceed the 12v supply.
Each led has a long and a short leg on it [ the short is the NEG. and the long is the live] and whilst you do need resisters in most isolated cases........ by Daisy chaining you remove all that faffing around
Visit their web site there is a wealth of info there . different sizes....... have differing values / voltage requirements ......and they can supply a micro cable to wire these all in tidally without ending up with a RATS NEST
Hope this helps and whilst I can assist.... the best way is to learn from scratch[ and its retained better] and all this info is explained to you easily .....