Do you mean the removeable (usually slatted) wooden floorboards? I am assuming that you have an old DAY SAILER I? If so, I'd check out the DSA web site (
www.daysailer.org) for ideas, it sounds like you plan to race and if anyone would have great ideas about replacing the floorboards.... the active racers on the DS Class web site will be the ones! However, most racers tend to leave the floorboards ashore while racing, since every little bit of weight "slows them down" <grin!>. From what I can find, the Class Rules do not include the weight of the floorboards in the minimum weight of 575#, so they are not "required".
The 628# figure is what O'DAY listed as minimum "trailering" weight, that is boat, mast, boom, rudder, sails, and floorboards. Maximum crew weight would be around 600-900# if you take the figures that O'DAY listed of a crew of 4-6 people (150# ea.).
575# is the minimum weight of the boat to be "class-legal", but there is no maximum weight figure, except for the weight of the centerboard can not exceed 25#.
I believe the original floorboards were mahogany strips or plywood, but I've heard of some owners who replaced them with other materials, including pine wood.
If you need to replace the rudder, the easiest way is to order one from D&R Marine (
www.drmarine.com) or from Cape Cod Shipbuiding (
www.capecodshipbuilding.com) neither will be cheap, but the rudder from CCSB will definitely be class-legal and the D&R one "should" be (but be sure Rudy does make the correct one!). If you decide to make your own, it should be much less costly, however be sure to consult the drawings contained in the DSA Handbook (Measurement Specs) as posted on the DAY SAILER Class web site.