Boat hardtop plans custom boat hardtops | atlantic towers, real fiberglass and aluminum boat hardtops. get away from bimini tops. custom size and shape. ready to bolt on with simple tools. light, strong, priced right!.. To sail the boat properly, i need ready access to the mizzen boom and sail from the cockpit. this requires some kind of opening through the bimini top. i had accomplished this in my original sunbrella bimini with zippered “hatch flaps,” and i incorporated them into the after-section of my new hardtop as well. but to cover the two forward. S&s marine in norfolk, va offers custom boat hard tops for grady white, tiara boats & other sport fishing boats. we offer custom marine fabrications..