also indicates that at 45 knots the hull has less drag with a trim of 5 degrees than 4 degrees the balance of the tests at a trim of 6 degrees did not result in any less drag than the 5 degree trim this indicates that the optimum trim for the hull should be somewhere 5 and 6 degrees at 45 knots based on the trimming moments the hull should trim in the area of about 5 8 degrees at 45 knots this is demonstrated by the charts of fig6 and 7 it is seen that the trim is substantially the same on the vessel operating at 45 knots whether it is set at 5 degrees or 6 degrees fig8 11 demonstrate the pressure distribution on the hull in the various conditions tested the stippled areas on the hull represent increasing pressure forces on the hull with increasing stippling in fig8 the pressure distribution on the hull trimmed at 4 degrees and moving at 30 knots is illustrated fig9 illustrates the pressure distributions on the same hull under the same conditions with only the 4 inch sideplates extending rearwardly from slightly behind the longitudinal center of gravity as seen therein there are some scattered pressure gradients adjacent the sideplates fig1 shows the pressure distribution on the hull with the keel deflected at 3 degrees and no sideplates as is apparent the pressures at the bow are less due to the hull starting to.