Motor boat designs & plans for motor boats 21′ to 30′ in length see the next design below. the hull has a double chine u/v bottomed shape giving an easy riding. Double eagle. don’t be fooled by the traditional, well balanced lines of our double eagle design. underneath her timeless appearance lies a modern hull that can be. The osprey double and triple kayaks are great light weight tandems for families who wish to kayak with kids or for kayaking with dogs. available as kayak kits or as.