How does the hull shape of the Shannon 38 SRD compare with existing powerboat hull shapes?
Before the SRD hull design, there were three types of powerboat hull shapes displacement-like long distance trawlers, semi-displacement-like lobster boats, and planing boats that reach speeds from 15 knots to 100 knots depending on engine size. Displacement hulls are used for long distance powerboats, and while are they very fuel efficient, their speed is limited by the laws of physics to a speed measured in knots of no more than the square root of the vessel’s waterline multiplied by 1.4. A 38′ displacement hull will have a top speed of 8.6 knots. The hull sections of displacement hulls are a relatively similar U shape from the bow to the stern. Displacement hulls are very uncomfortable in even moderate conditions as they roll excessively in beam seas requiring complicated and expensive stabilizing devices Semi-displacement hulls are best known as lobster boats and coastal trawlers and exhibit slightly better speeds (a top speed in knots of no more than the square root of the vessel’s
