Boat Handling • Discovering the relationship between the laws of physics and boat behaviour can be perplexing. • No two boats respond the same, even under identical circumstances. • Successful boat handling requires Practice, Practice and More Practice.
Helmsmanship • It cannot be mastered from a book or in a classroom. • It involves your “reaction - response” to the entire boat and its total environment including the weather. • You must attain the basics of “performance” from “hands on” experience in order to fully understand and master the “helm”.
Secrets of Good Helmsmanship • KNOW YOUR BOAT • Take it easy on another boat, until you “get the feel” and KNOW THEIR BOAT • Practice, practice and practice some more.
Terminology 1 • INBOARD: Engine mounted within the hull. Fixed directions of thrust ahead and astern. Steering generally uses rudder • OUTBOARD: Engine mounted on the transom and detachable.Thrusts ahead and astern, but whole engine can be moved to steer. • I/O: Combination of inboard and outboard. • THRUST: Force moving the boat through the water, gained by a propeller or water jet.
Terminology 2 • PROPELLER: A “screw” which, when rotating. draws in water from ahead and pushes it out astern. • WATER JET: A screw inside a housing that sucks water from under the vessel, and pushes water out of a nozzle on the transom to propel. Steering is achieved by turning the nozzle, slowing or going astern is by moving a bucket down in front of the nozzle to redirect the flow.
Terminology 3 • SINGLE SCREW: Boat with one propeller. • TWIN SCREW: Boat with two propellers.
Terminology 4 • STEERING: Accomplished by changing direction of thrust, whether by: • 1 using rudder on inboard engine. • 2.changing direction of propeller thrust on outboards or inboard/outboards. • 3.changing direction of nozzles and buckets on water jets.
Terminology 5 • PORT - left side of the boat looking forward. • STARBOARD - right side of the boat looking forward. • REMEMBER: PORT and STARBOARD sides are fixed, no matter which heading you have.
Terminology 6 • MAKING HEADWAY: Going forward in the water • MAKING STERNWAY: When backing down. • TURNING TO PORT: Bow is moving to the left. • TURNING TO STARBOARD: The bow moves to the right.
Terminology 7 • RIGHT HAND PROPELLER: Screws through the water in a clockwise rotation, looking at the transom from the stern. • LEFT HAND PROPELLER: Screws through the water in an anti-clockwise rotation, looking from aft. • Most single engine boats have RIGHT HAND props on them.
Terminology 8 • TWIN ENGINED: Usually have counter-rotating props to offset torque with RIGHT HAND propeller on starboard side, LEFT HAND propeller on port side.
Suction Screw Current • SUCTION: Incoming water current FROM forward of the propeller • DISCHARGE: Outgoing current aft of the propeller • RUDDER(S) are placed in the center of the DISCHARGE flow and the current of water rushing by produces a pressure on the rudder blade which controls the direction of the boat moving in the water.
Suction Screw Current • NOTE: RUDDER(S) are ONLY EFFECTIVE, when the boat moves through the water.
Propellers • RIGHT-HANDED: View from stern. Propeller is turning CLOCKWISE (NOTE OUTSIDE TIP AT TOP) • LEFT-HANDED: Turning COUNTER-CLOCKWISE.
Transverse Thrust • When moving forward: • RIGHT HAND propellers produce greater thrust to starboard at the stern • and • LEFT HAND propellers produce greater thrust to port at the stern. • All propellers rely on smooth flow of water for max efficiency.
Transverse Thrust • When moving astern: • RIGHT HAND propellers produce greater thrust to port at the stern • and • LEFT HAND propellers produce greater thrust to starboard at the stern. • This fact can be used in manoeuvring on and off docks,
Transverse Thrust • This called transverse thrust or the paddle wheel effect.
Transverse Thrust • In a right handed propeller, moving ahead, torque will move the stern to the right. • Visualize the direction of movement of the top of the prop for direction of movement of stern.
Transverse Thrust Green spot is centre of rotation for this manoeuvre
Transverse Thrust • This transverse thrust may be used to best effect when docking, to bring the stern alongside.
Handling Characteristics • HEAVY BUILT: Displacement, load carrying hulls. Stable. Slower. • LIGHTER BUILT: Planing; Sport hulls. Shallower draft. Much faster. Less stable. • BOTH: Handle completely differently, especially in heavy weather • PLANING hulls revert to displacement hulls at low speeds.
Handling • ALL HULLS are affected by WIND and CURRENT. • HIGH BOWS: Tend to fall off the wind NO MATTER what is done to prevent it, especially at low speeds. • CURRENT: Biggest reaction factor in all hull types. • DISPLACEMENT HULL: Current greatest affecting factor
Handling • The more structure above the water, the more effect from wind. • The deeper the draft, the more effect from current. • Effect of current is greater than effect of wind on displacement hulls. • Effect of wind greater than current on planing hulls.
Mooring Lines • BOW LINE: Stops the bow from moving aft • BOW BREAST: Stops the bow from moving outward from the dock. • AFTER BOW SPRING: Stops the boat from moving forward • FOREWARD QUARTER SPRING: Stops the boat from moving back
Mooring Lines • AFTER BREAST: Stops the stern from moving out from the dock • STERN LINE: Stops the stern from moving forward
Springing or Warping onto a Dock 1 • To get alongside starboard to, bend a mooring line to a bow cleat. When close to the dock, pass it to a person on the dock from the starboard bow to secure it to a cleat or bit on the dock. • Shorten the line on the boat side to suit and cleat it off. • Put the rudder to PORT and give the engine moderate power AHEAD.
Springing or Warping onto a Dock 2 • The left rudder will swing the bow out. • The power will move the boat ahead until it is stopped by the mooring line • The shortened mooring line will force the hull into the dock and stop it’s forward motion.
Take It... SLOW !
Without Wind Or Current • Approach the dock at a very slight angle (10 to 20 degrees) • When the bow is close to dock, shift into reverse to slow headway • Ease into the landing
Wind or Current off Dock Approach the dock slowly at a fairly sharp angle (about 45 degrees) At the dock, shift into neutral and secure a bow line Turn hard in the direction away from the dock Slowly go forward against the bow line The stern will move toward the dock
Into the Wind or Current • Approach the dock at a slight angle (20 to 30 degrees) • When the boat is close to the dock, turn the boat so that it is parallel to the dock • Put the bow line over first • The stern will then swing into the dock
With Wind or Current Astern Approach the dock at a slight angle When the bow is close, use reverse to slow headway Make fast the stern line Make fast the bowline THIS APPROACH IS VERY DIFFICULT AND SHOULD BE AVOIDED Be ready to use reverse gear at all times
Wind or Current on to the Dock • Approach parallel to the dock • Shift into neutral • Let the wind and the current carry the boat into the dock
Springing Or Warping Out 1Port Side To 1. Let go all lines except short forward spring, well cleated. 2. Port rudder to swing the stern away from the dock. 3. Low power to move the boat’s stern out from the dock.
Springing Or Warping Out 2Port Side To 4. Short spring will stop the outward motion, and swing the hull on the forward cleat to a position bringing the stern off the dock. 5. Let go the forward spring line. 6. Go astern to depart the dock.
Turning Around 1 1. The vessel can be turned around in a confined space by using transverse thrust to its maximum. 2. The sticks can be split, one engine going ahead, the other astern.
Turning Around 2 3. The vessel will start turning around the centre of rotation. 4. There can be drift ahead or astern, which may be minimised by increasing the rpm on the astern engine or ahead engine respectively.