this set of plans does not include a specifications list for the dark harbor 12 1/2. so you will be guessing on a number of things like how much lead or iron do i add to the keel as no weights are available with the plan. only people who builds boats on a daily biases should attempt to build this as no explanations for fittings are included for :keel,stem,transom knee,fin,floors,rudder tube and a great deal of other things. i would definitely call before ordering a set of advanced plans to make sure materials list is involved if you are building boats for the first time. i decided that i would make this my first boat to build despite never building one before because I like challenging myself and learning new things, of course this would be a multi year build along with reading a bunch of books on boat building, however there are no fine building details for a boat like this(i was really in love with this one too because it's a mini j class!) so I think I'm going to move back a little and try the marshcat 15 or the haven 16 or melonseed 16 instead as these boats have complete plans.
