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anchoring - page 1

5.1 Boat handling

A yacht (sailboat or motorboat) should execute some special handling, most of the times with the motor, to anchor. The most basic of these are:

  • Anchoring in a bay.

  • Anchoring (with the stern), on a pier or on other boats.

  • Anchoring  (with the bow), on a pier or on other boats.

  • The along side mooring (side by side), on a pier or on other boats.

  • Departure from all the above.

In order for all the above to be done correctly and effectively, the captain must have the ability to control the his boat in limited spaces and at low speed. Boats behave differently depending on their type (sailboat, motor, catamaran) but there are the following key factors common to all boats.

  • Number of available engines (one or two).

  • Power of the engine(s).

  • Shape and size of the rudder.

  • Shape of the hull.

  • Weather conditions during the anchoring.

When things go wrong during anchoring, it is better to take no action than to do something that will further aggravate the situation, something that usually happens when the captain is inexperienced. Experience is a key factor in the ability of any captain and it takes a lot of time, effort and practice to gain. In the beginning, small and easy steps are needed, making short trips together with someone more experienced than you. The secret to a fast and efficient evolution is the observation of space, the notes, the reading, the questions to someone more experienced and the repetition.

RUDDER

When a boat is moving, a flow of water is created around the rudder in the opposite direction of movement. As long as the rudder is not turned and is in the middle, due to its hydrodynamic shape, no force (resistance) develops on it. However, if the rudder is turned, the flow of water is diverted in the direction of rotation, resulting in a force that is perpendicular to the rudder surface, the magnitude of which depends on the water flow velocity, the rudder angle and the size of the rudder surface. The ability for every boat to turn depends mainly on the type, size and position of the rudder. As a rule in all boats, the propeller is placed in front of the rudder.

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PROPELLER

Normally, the propeller rotates clockwise as viewed from astern when the boat is going forwards. This is known as a right-handed propeller. Some propellers rotate anticlock-wise when the boat is driven forwards and are known as left-handed propellers. When the propeller rotates in forward, it throws out a slipstream astern. This causes a counter force (reaction) which drives the boat forwards. In addition, the propeller tries to paddle across sideways in the direction it is turning. A right-handed propeller will pull the stern to starboard when going ahead and to port when going astern. In order to understand the paddle effect better, imagine that the propeller touches the seabed and rolls sideways, rather like a wheel. This is known as the paddlewheel effect and is very important in the handling of the boat. The effect is greater with large, slowly rotating propellers and is more marked when going astern. Propellers come in many shapes with both fixed and movable blades. Propellers with 2, 3 or 4 blades are most common.

 

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The clockwise propeller propels the stern to the left during reverse

WIND IMPACT

When the boat is not making its way through the water and the engine is in neutral, the bow of a sailing yacht will normally be blown off the wind and end up with the wind on the quarter. This happens because the hull is not as deep forward as aft and because the mast is located relatively far forward.  

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ENGINE HANDLING

Manoeuvring in confined spaces:

  • Use short, strong bursts of engine power.

  • Always leave the control in neutral 1-2 sec.

  • Try to stop any movement forward or astern. 

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