Before I bought hull #48 I came across two other J/30's for sale. None (including the one I bought) had water problems in the transom. Pretty much all of the
J/Boats built form the late 70's through the 80's you need to check carefully for potential balsa core rot. My 1987 J/27 needing extensive re-coring in the hull_(not a fun job) fortunately the J/30 I found the original owner had done an epoxy bottom job right from the get go_.that makes a huge difference.