The combination of high speed (100-200 knots) and long range (10,000 miles) required for a modern sealift ship requires a lift/drag (L/D) ratio greater than 32. Only a hydrofoil craft can achieve this (i.e. L/D greater than 40 for the foil alone). A recent surface proximity hydrofoil theory suggests (in contrast to the traditional theory) that large span foil with a conventional sub-cavitating foil section can reach these speeds without cavitating. Our proposed Phase I includes experiments which will resolve this question. If it turns out that the new surface proximity theory is incorrect, it is still theoretically possible to achieve the required performance with the "planning foils" (atmospherically vented upper surface and hence no possibility of cavitation) which we are developing. The ride of conventional hydrofoil would be intolerably rough in a seaway at 100-200 knots. We have been developing a foil suspension system during the last several years which avoids this and other problems, using a four ton "Dynafoil" prototype boat. We propose to design a second a second prototype during Phase I which, built early in Phase II, will serve as a demonstrator for the technologies critical to a full size sealift ship. Since two independent investors have already contributed nearly one million dollars to this program, it's anticipated that Phase II could be co-sponsored under the new DoD Fast Track procedure.
