Some(?all?) clubs also have a set of dates the boat must have been built/launched/whatever between to be legal. Read your clubs rules, or the club you are most likely to join. They will answer a lot of questions for you.
For IRCWCC rules, a ship must have been launched between 1905-1946 inclusive,and been completed. They have a ship list: http://www.ircwcc.org/sln/sl.htm Which may or may not reflect current rules. Should be close anyway.
WWCC has grandfathered an Alcies and has given permission to have a Kruzer P. I am not sure if the Dutch Battlecruisers were laid but,one of those is in operation.
The Germans were supplying a good chunk of the material for the Dutch BC's. Hoever, war broke out and the Netherlands were invaded prior to the ships being laid down.
Treaty allows for any ship that was ordered by a recognized government. While I personally dislike the hypothetical ships, some guys do like them and I see no good reason to tell someone they can't build a ship that they like. I'd by far rather have someone build a Montana that I dislike because it wasnt built, then decide to fly RC airplanes instead. More options is a good thing.
That is interesting about the Dutch BCs. See in the WWCC if they were not laid down you can not build them or something like that. Very interesting.
The WWCC requires "accepted designs by any navy between the calendar years 1900 and 1946 and whose keels were laid down" that are also "clearly defined in Conways." Funny, despite that bit about "whose keels were laid down," the clause about hypothetical ships reads: "Any ship model based on a hypothetical ship (defined as a ship listed in Conway’s but the keel of which was never laid) whose basic information is depicted in Conway’s."
The Buckeye Battle Squadron rules say any ship that had a keel laid down from 1905 to the end of 1946.
