Re: What Size Dock Lines do I Need ?
I would expect 5/8th all around should be OK for that size boat. I have a heavy 31 and personally I also have two spring lines on each side (total of 10) but I am paranoid. OK a couple of them are 3/4 but no one else I have seen does that around here. Almost all boats your size here have all 1/2 inch with only two lines on each side. (San Pedro CA).
Are you sure that the problem was not chafe that was already there before the wind got strong? Of course thicker lines give you more time to discover chafe but the lines you have should handle wind if they are in good shape.