swinewine
25.05.2021 1:59:02
Once on plane, it’s time to trim up to raise the bow so that the boat is skimming along over the water, rather than pushing through it. here
See full version: How to Trim a Boat
Once on plane, it’s time to trim up to raise the bow so that the boat is skimming along over the water, rather than pushing through it. here
An experienced captain gets in the habit of trimming the drive or outboard all the way down every time the boat comes off plane, so that it’s in position when it’s time to power back on plane. Automatic trim systems, a feature of many newer boats that can also often be added as an accessory, effectively manage the trim based on boat speed and throttle setting.
Many new boaters often ask the question, "what does 'trim' mean"? Knowing what it means to trim a boat, and how to properly trim a boat, will improve its performance and fuel economy. Trim is simply the running angle of the boat as it makes way in the water; when we adjust the trim we are either raising or lowering the bow (the front of the boat). Here’s how it works.
Negative trim—when the trim is all the way down—is used to help get the boat on plane as it accelerates away from dead in the water. The angle of the propeller thrust will help lift the stern and push the bow down so that the boat rolls smartly up onto the water.
Try to power on plane with the drive trimmed out, and the prop will dig a hole behind the boat and the bow will point skyward, probably blocking your view forward, as the boat struggles to plane. You may get on plane eventually, but you are wasting fuel and putting undue stress on the engine.
Another important difference is that water is essentially incompressible while air is very compressible. This makes it much harder to move through water as the water has to have somewhere to go. It can’t just be squeezed. Folding it aside at the surface is even more important.
A surface vessel is more subject to wind and waves than a deeply submerged submarine. Wind and waves act to deflect the hull from the desired course.
Submarines have blunt tips and look more "airfoil-ish" because they operate underwater where the distinction between moving through air and water is minimal. There are therefore many parallels between the external aerodynamics of a wing and the external hydrodynamics of a submarine. As @Cutter Ketch mentioned, the bow of a surface ship that remains under the water often looks like this, too. here
Pretty much. Note that many also have under-surgace bulges, so you have a bit of both:
https://en.m.wikipedia.org/wiki/Bulbous_bow
The left side of a pleasure craft looking forward. More information on port side.
Safety of Life at Sea (SOLAS) lifejackets meet very high performance standards and are approved for all vessels. The SOLAS will turn you on your back in seconds to keep your face out of the water, even if you are unconscious. They come in two sizes, for those over 32 kg (70 lbs) and those less than 32 kg (70 lbs). They are available in comfortable and compact inflatable configurations that can be automatically, manually or orally inflated. [links]
Sustained wind speeds in the range of 20 to 33 knots inclusive, as defined by Meteorological Service of Canada.
When calling the starting line, make sure the guys in the back know what your hand signals mean. Review these before the start just to be sure. Use a line sight if possible. This helps confirm where you are on the line. Also, understand the acceleration characteristics of your boat in the conditions in which you're sailing. Before each start, practice timed runs at the starting line so the whole team can feel how the boat will get up to speed. more
Develop your team within the team. The job of getting the sails up and down often falls on a specific portion of the crew. Make sure those sailors (bow, mid-bow, mast, pit, floater, etc.) are all on the same page and know what to do in any situation. more
Take notes! If you sail different types of boats, take notes on how they are rigged (are the guys led inside or outside of the lifelines) and how the boat is sailed (do inside or outside jibes). Reading these notes before you go practice allows you to maximize your time on the water and not waste time re-learning how to sail the boat.
Debrief at the end of the day. Whether with the whole crew, just your bow team, or by yourself, go through the day and identify the good and bad and how things could have been done differently or more effective. [links]