The skill of the pilot in the boat can be instrumental in navigating safely and fairly comfortably even in less than ideal conditions. It is difficult to give valid directions for any type of boat, because each has its own technical characteristics and different reactions. There are boats that can be easily steered even by the inexperienced and others that will never be able to deliver good performance on the rough seas, even when steered by the best skipper. Differences are determined by hull type (displacement or planing), type, weight arrangement, transmissions, and propellers.
Related articles
- The two who crossed the Atlantic on a 4-meter boat.
- Flaps in boats, what they are and how to use them
Boat with waves in the bow
Situation where keeping navigation comfortable is often difficult. How should trim and flaps be adjusted to deal with waves at the bow or jaw? Whether with outboard engines, surface drives or stern drives, the trim should be held in the lowest possible position so that the propeller thrust tends to keep the hull parallel to the surface of the water, avoiding bow gybing. The same effect is achieved by lowering the flaps. Care must be taken not to overdo it, however, because the combined use of these two adjustments could lead to excessive lowering of the bow with the danger of “sticking” the waves.
Regarding gait, an important distinction must be made between hulls with sporting attitudes and heavier, almost displacement hulls. Fast boats usually have their center of gravity shifted more toward the stern, and with the wave in the bow they tend to beat frequently. Better behavior can be achieved at higher cruising speeds because the increased thrust of the propellers tends to “spread” the hull over the water, that is, allowing it to hold a more constant trim parallel to the sea surface. It is clear that the skill of the pilot and the quality of the construction are indispensable elements in the application of this theory. On the contrary, if you overdo the gait and if you do not have a suitable vehicle, you risk compromising the safety of people and the reliability of the boat. Instead, with heavy boats it pays to adjust the gait around the minimum glide speed, avoiding dropping the hull in displacement, but also giving up trying to find faster gaits that might only cause more discomfort to the crew and more stress to the structures.
Boat with the sea in the stern
When sailing with stern seas, the bow should normally be relieved, for example by draining any water tank (often arranged right at the front of the hull). At the same time, trim and flaps should be adjusted to keep the bow up, even as the boat descends into the cable, to prevent it from getting into a wave, resulting in flooding of the deck. With aft seas the adjustment of these two elements is generally very critical (also due to cavitation problems) and changes depending on the type of wave.
It is usually necessary to act alternately on both, until the best balanced condition is found, which also succeeds in reducing hull pitching. The gait must be high enough to keep the hull in glide and not to lose control of the boat. The effectiveness of rudders, in fact, depends precisely on the difference between the speed of the hull and the speed of the wave; by reducing one’s gait too much, the thrust of the swells could get the upper hand over steerability, with the risk of causing dangerous yawing. Just as in the case of a forward sea it may be more favorable to sail at the jaw, in the case of a stern sea it may be more convenient to choose a course that allows you to sail with the waves at the yard, rather than on the mirror.
HELP US KEEP YOU UP TO DATE
Motor Boats journalists, along with SAIL Newspaper e Top Yacht Design strive every day to ensure quality, up-to-date and correct information about the boating world free of charge through their websites.
If you appreciate our work, support us and subscribe to the magazine!
