Stretching the HM200 series SES

The HM200 series SESs are discussed and compared with respect to design specifications, cost, and performance specifications such as speed loss in waves, and vertical accelerations. Structural modifications for the HM221, demonstrating a capacity increases of 33 percent over the HM218 for only a 22 percent increase in first cost, include small increases on bottom shell thickness and a 30 percent lift power increase (by using the turbo charged version of the HM218 naturally aspirated engine). It is shown that the HM200 series requires about half the HP and fuel consumption of the catamaran, and about 30 percent less than the surface piercing hydrofoils, in the same speed range.