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SEAMANSHIP CH. 5 BOAT HANDLING. REFERENCES: Chapman’s and AUX study guide. RESPONDING TO THE LAWS OF PHYSICS. Discovering the relationship between the laws of physics and boat behavior can be perplexing. No two boats respond the same even under identical circumstances.
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SEAMANSHIP CH. 5BOAT HANDLING REFERENCES: Chapman’s and AUX study guide
RESPONDING TO THE LAWS OF PHYSICS • Discovering the relationship between the laws of physics and boat behavior can be perplexing. • No two boats respond the same even under identical circumstances. • Successful boat handling requires PRACTICE,PRACTICE and MORE PRACTICE.
ABILITY TO STEER WELL“HELMSMANSHIP” • Cannot be mastered from a book or in a classroom. • Involves your “reaction - response” to the entire boat and it’s 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”.
SECRET OF GOOD HELMSMANSHIP • KNOW YOUR BOAT • Take it easy on another’s boat until you “get the feel” and KNOW THEIR BOAT • Practice, practice and practice some more.
BASIC TERMINOLOGYINBOARD OUTBOARD I/O THRUST PROPELLER • INBOARD: Engine mounted within the hull • OUTBOARD: Engine mounted on the transom and detachable. • I/O: Combination of inside and outside. • THRUST: Force moving the boat through the water, gained by a propeller. • PROPELLER: A “screw” which, when rotating. draws in water from ahead and pushes it out astern
TERMINOLOGY Cont’dSINGLE/TWIN SCREW AUXILIARY INBOARD OUTBOARD • SINGLE SCREW: Boat with one propeller • TWIN SCREW: Boat with two propellers. • AUXILIARY: Sailboat fitted with an engine • INBOARD: Fixed direction of thrust, only changed by rudder action. • OUTBOARD OR I/O: Direction of thrust is changed by rotating the engine. Change of direction of thrust is the rudder.
TERMINOLOGY Cont’dSTEERING THRUST RUDDER PORT STARBOARD • STEERING: Accomplished by CHANGING direction of thrust. • CHANGING THRUST DIRECTION: • By rudder action • By changing engine direction of outboard or I/O lower unit. • REMEMBER: PORT and STARBOARD sides are fixed, no matter which heading you have.
TERMINOLOGY Cont’dHEADWAY• STERNWAY• TURNING•RIGHT/LEFT RUDDER • 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. • RIGHT OR LEFT RUDDER: Direction the bow turns to.
TERMINOLOGY Cont’dRIGHT/LEFT HAND PROPELLERS SINGLE/TWIN ENGINES • RIGHT HAND PROPELLER: Screws through the water in a clockwise rotation, looking at the transom from the stern. LEFT HAND( the opposite). • Most single engine boats have RIGHT HAND props o n them. • TWIN ENGINED: Usually have counter-rotating props to offset torque with RIGHTHAND prop on starboard, left hand prop on port side. Without counter-rotating props vessel would be almost impossible to steer.
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. • 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.
PROPELLERSTORQUE, EQUAL / UNEQUAL BLADE THRUST When moving foreword, RIGHTHAND props produce GREATER thrust to starboard at the stern AND LEFTHAND props produce Greater thrust to Port at the stern. ALL PROPELLERS RELY ON SMOOTH FLOW OF WATER for max efficiency.
EFFECT OF TORQUE BY SINGLE SCREW – RIGHT HAND TURNINGPROPELLER – MOVING FORWARD • TORQUE will move the stern to the right. • ALWAYS visualize the DIRECTION OF MOVEMENT OF THE TOP of the prop for DIRECTION OF MOVEMENT OF STERN.
HANDLING CHARACTERISTICSPLANING Vs. DISPLACEMENT HULLS • 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 Cont’dWIND•CURRENT Vs. HULL TYPES • HANDLING: ALL HULLS 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 Cont’dEXPOSED HULL AREA Vs. WIND • DRAFT• CURRENT • 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 TO STERN • 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 foreword • FOREWARD QUARTER SPRING: Stops the boat from moving back • STERN BREAST: Stops the stern from moving out from the dock • STERN LINE: Stops the stern from moving foreword
SPRINGING OR WARPING INTO • WARPING: Bend a mooring line to a bow cleat and pass it to a person on the dock to secure it to a cleat or bit. • Shorten the line on the boat side to suit and cleat it off. • If you’ve done this on the starboard side, put the rudder to PORT and give the engine moderate power AHEAD. • 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 ! CLICK
With Wind or CurrentFrom the Dock DEPLOY FENDERS 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 CLICK
WITHOUT WIND OR CURRENT • DEPLOY FENDERS • 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 CLICK
Into the Wind or Current DEPLOY FENDERS 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 landing CLICK
With Wind or Current Astern DEPLOY FENDERS 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 CLICK
WIND TOUGH !!! AVOID !!!
With Wind or Current Toward the Dock DEPLOY FENDERS Approach parallel to the dock Shift into neutral Let the wind and the current carry the boat into the dock CLICK
SPRINGING OR WARPING OUTSTERN FIRST • RIGHT rudder • SHORT after bow spring, well cleated on both ends • RIGHT RUDDER to swing the stern away from the dock • LOW power to move the BOAT out from the dock. • Short spring will stop the outward motion and swing the hull on the forward cleat to a position almost perpendicular to the dock. • Release the dockside spring line. • You’re on your way in reverse.
REVIEW QUESTIONS NO. 1 • The part of the current that flows into the propeller is called the ___ _____ _____. • a. back lash current • b. back tide current • c. suction screw current • d. post screw current
REVIEW QUESTIONS NO. 2 2. When a right-handed propeller is turning clockwise, the boat will go _________. a. forward b. backward c. to the right d. to the left
REVIEW QUESTIONS NO. 3 3. The stern of a single screw boat with a left hand propeller tends to go _______when the propeller is reversing. a. to starboard b. to port c. ahead d. up
REVIEW QUESTIONS NO. 4 4. When the rudder is put over, the stern is _____ the direction the rudder moves. a. kicked toward b. kicked away from c. kicked in d. not affected by
REVIEW QUESTIONS NO. 5 5. When backing a single screw inboard with a right-handed propeller and rudder amidship, the stern will___________ a. go to starboard b. track straight back c. drift to starboard d. move to port
REVIEW QUESTIONS NO. 6 6. The mooring line that keeps the boat from going ahead is the _____ a. Bow line b. Forward spring c. Breast d. after bow spring
REVIEW QUESTIONS NO. 7 7. By going ahead on one engine while reversing the other enables a twin screw vessel to_______ a. turn in a much wider area b. turn within it’s own length c. turn within 1/3 of it’s own length d. back easier
REVIEW QUESTIONS NO. 8 8. Getting away from a dock, when the boat is being set into it by the wind, generally requires using_____________. a. an after bow spring line b. a breast line c. a boat hook d. a stern line
REVIEW QUESTIONS NO. 9 9. Breast lines are set ________ the boats hull. a. parallel to b. next to c. perpendicular to d. at 45 deg. angles to