Hello Apex,
The 1968 edition of The Sailboat Classes of North America says the following about the Interlake: "The 18-foot Interlake sloop, designed by Francis Swiesguth in 1932, came before the planing class erabut has survived. Since being converted from wood to fiber glass in 1955, she has become one of the fast-growing classes. With a hard chine and no "freak characteristics", as someone has described her, she has good stability and is a good all-around boat." Vital Statistics: LOA 18' waterline 15' 3" beam 6' 3" draft without centerboard 8" with CB down 4' 8" sail area 175 sq ft (no spinnaker) weight 650 lb trailerable; racing crew two or three
I have never sailed an Interlake, but it looks like a beautiful, dry boat that would be fun for anyone. We owned several Celebrity Class sailboats over the years and the Interlake seems similar although it is described as hard-chined whereas the Celebrity is not. Personally, I would rather see a person "in" a boat like that rather than "on" a board boat like the sunfish.
Will the boat stay in the water? On a mooring or on a dock will put some stresses on the hull and the rigging. A frequent check of the rigging would be in order. We bought one of our Celebrity Class boats cheaply because the mast had fallen and damaged the foredeck while the boat was on a mooring. If the boat is hauled out after each use then Mom will probably need help to do that although 650 pounds isn't too much boat to move. That depends on trailer and launch ramp location. The Interlake will probably offer an opportunity for one or more people to accompany her. Best Wishes.
RE: cockpit sole delamination. Depends on how it is built. If it is laminated with wood between the layers you will have a real project to remove the inner layer and remove/dry the filler. Not impossible, but a serious job. If you can remove the "floor" layer in large pieces you can epoxy those pieces back into their respective places.
Final thoughts: (1) sail the Interlake as it is for a while assuming it does not become waterlogged due to the delamination. (2) Let Mom decide. If she wants to sail the Sunfish let her do it.
