3-23EEMU19160Trim angle settings and boat handlingWhen the boat is on plane, a bow-up atti-tude results in less drag, greater stabilityand efficiency. This is generally when thekeel line of the boat is up about 3 to5 degrees. With the bow up, the boat mayhave a greater tendency to steer to one sideor the other. Compensate for this as yousteer. The trim tab can also be adjusted tohelp offset this effect.1 Optimum angle (level keel line)2 Bow up3 Bow downBow UpToo much trim-out puts the bow of the boattoo high in the water. Performance and econ-omy are decreased because the hull of theboat is pushing the water and there is moreair drag. Excessive trim-out can also causethe propeller to ventilate, which reduces per-formance further, and the boat may “por-poise” (hop in the water), which could throwthe operator and passengers overboard.Bow DownWhen the bow of the boat is down, it is eas-ier to accelerate from a standing start ontoplane. Too much trim-in causes the boat to“plow” through the water, decreasing fueleconomy and making it hard to increasespeed. Operating with excessive trim-in athigher speeds also makes the boat unstable.Resistance at the bow is greatly increased,heightening the danger of “bow steering” andmaking operation difficult and dangerous.NOTE:@Depending on the type of boat, the outboardmotor trim angle may have little effect on thetrim of the boat when operating.@
