View tunnel hull boat plans for the seabright 21, a shallow draft, atkins style tunnel boat. see our plywood version of this tunnel boat design at bateau!. Tunnel hull 13: a family line of high performance tunnel hulls, designed to move out in all water conditions at all speeds. wide transom and deep tunnel make for. [cs25] the carolina sportfish 25 is an offshore boat based on the carolina sport fishing boats lines..