Authorised bruce roberts international yacht design web site operated by bruce roberts-goodson the designer, plans and kits for sailboats, powerboats for building in. While the tunnel boat derives much of its high performance from air lift, it depends at the same time on its planing interaction with the water to maintain a stable. Free study plans for the tortuga mullet skiff. our study plans are two of the actual construction drawings. they’re not enough information for you to build the boat.