The input of marine trimmers must always be sought when doing any design modifications to a boat or water vessel. According to experts, there are many poorly trimmed boats operating today. A lack of information means not many people understand whether their boats are well trimmed or not. Trimming the boat is a matter of safety. The more open the waters, the more important it is to properly trim a boat. In extreme conditions, the trim could be the difference between staying up and overturning. It is however, difficult to reach these extremes due to the strict standards of the marine industry and boat manufacturers. Still, the trim should not be taken any less seriously, especially when it can be helped by the boat owner or operator.
Before the boat begins to move, it is common sense that it should be level or square. Trim has to do with the weight distribution, and this should start from when it is stationery, during the installation of marine upholstery, loading accessories and people. Common sense dictates to never have a boat with all the passengers seated on one side. The poor weight distribution will cause bad steer and an uncomfortable ride. People can easily be moved, together with anything that is not bolted down. Sometimes, one will have to move the fuel tanks and ice boxes around as they are emptied with continuous use. Sometimes, the distribution can be allowed to make the boat stern heavy. This is especially helpful when there is an emergency or when under tow.
Trim is unlike simple automobile repairs like car roof lining repair. While stationery trim is a matter of common sense, as the boat hull begins to move, the idea gets more complex. The concept is still the same, but with the speed increasing and the continued interaction between the boat hull and the wind and waves, the hydro and aerodynamics come into play. The trim for travelling in one direction relative to the direction of the wind or flow of water might not be appropriate for another direction with the same boat. This is why despite the fact that many people dislike it; many boats come with a trim button. Especially in powerboats, it is useful being able to adjust the trim according to the prevailing conditions.
Two common ways can be used to adjust the trim of a powerboat at speed. The most common are the trim tabs. Trim tabs are found on the transform, or in a recess at the bottom of the hull for larger boats. They are adjustable and use the same working mechanism of aircraft elevators. The other method through which trim can be adjusted is through the change of the angles of the stern drive leg compared to the transform.
If the outboard is small, it can be adjusted manually through the movement of a pin on a mounting bracket. Larger boats might require stern drives and outboards that are controlled electronically or through hydraulics at the touch of a trim button on the boat.