Transcript 06.3 & 06.5 Boat Handling

BOAT HANDLING
Boat Handling
Boat Handling
1. Discovering the relationship between the
laws of physics and boat behaviour can be
perplexing.
2. No two boats respond the same, even under
identical circumstances.
3. Successful boat handling requires Practice,
Practice and More Practice.
Helmsmanship
1. It cannot be mastered from a book or in a
classroom.
2. It involves your “reaction - response” to the
entire boat and its total environment including
the weather.
3. You must attain the basics of “performance”
from “hands on” experience in order to fully
understand and master the “helm”.
Secrets of Good Helmsmanship
1. KNOW YOUR BOAT
2. Take it easy on another boat, until you “get
the feel” and KNOW THEIR BOAT
3. Practice, practice and practice some more.
Terminology
Terminology 1
1. INBOARD: Engine mounted within the hull. Fixed
directions of thrust ahead and astern. Steering
generally uses rudder
2. OUTBOARD: Engine mounted on the transom and
detachable.Thrusts ahead and astern, but whole
engine can be moved to steer.
3. I/O: Combination of inboard and outboard.
4. THRUST: Force moving the boat through the water,
gained by a propeller or water jet.
Terminology 2
1. PROPELLER: A “screw” which, when rotating. draws
in water from ahead and pushes it out astern.
2. 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
1. SINGLE SCREW: Boat with one propeller.
2. TWIN SCREW: Boat with two propellers.
Terminology 4
1. 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
1. MAKING HEADWAY: Going forward in the
water
2. MAKING STERNWAY: When backing down.
3. TURNING TO PORT: Bow is moving to the
left.
4. TURNING TO STARBOARD: The bow moves
to the right.
Terminology 7
1. RIGHT HAND PROPELLER: Screws through
the water in a clockwise rotation, looking at
the transom from the stern.
2. LEFT HAND PROPELLER: Screws through
the water in an anti-clockwise rotation,
looking from aft.
3. Most single engine boats have RIGHT HAND
props on them.
Terminology 8
1. 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
1. SUCTION: Incoming water current FROM
forward of the propeller
2. DISCHARGE: Outgoing current aft of the
propeller
3. 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
1. NOTE: RUDDER(S) are ONLY EFFECTIVE,
when the boat moves through the water.
Propellers
1. RIGHT-HANDED: View
from stern. Propeller is
turning CLOCKWISE
(NOTE OUTSIDE TIP AT
TOP)
2. 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
1. This called transverse thrust or the paddle
wheel effect.
Transverse Thrust
1. In a right handed
propeller, moving ahead,
torque will move the stern
to the right.
2. 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
1. This transverse thrust may be used to best
effect when docking, to bring the stern
alongside.
Handling Characteristics
1. HEAVY BUILT: Displacement, load carrying hulls.
Stable. Slower.
2. LIGHTER BUILT: Planing; Sport hulls. Shallower
draft. Much faster. Less stable.
3. BOTH: Handle completely differently, especially in
heavy weather
4. PLANING hulls revert to displacement hulls at low
speeds.
Handling
1. ALL HULLS are affected by WIND and CURRENT.
2. HIGH BOWS: Tend to fall off the wind NO
MATTER what is done to prevent it, especially at
low speeds.
3. CURRENT: Biggest reaction factor in all hull
types.
4. DISPLACEMENT HULL: Current greatest
affecting factor
Handling
1. The more structure above the water, the
more effect from wind.
2. The deeper the draft, the more effect from
current.
3. Effect of current is greater than effect of
wind on displacement hulls.
4. Effect of wind greater than current on
planing hulls.
Mooring Lines
1. BOW LINE: Stops the bow from moving aft
2. BOW BREAST: Stops the bow from moving
outward from the dock.
3. AFTER BOW SPRING: Stops the boat from
moving forward
4. FOREWARD QUARTER SPRING: Stops
the boat from moving back
Mooring Lines
1. AFTER BREAST: Stops the stern from
moving out from the dock
2. STERN LINE: Stops the stern from moving
forward
Manoeuvring On/Off Docks
Springing or Warping onto a
Dock 1
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.
2. Shorten the line on the boat side to suit and cleat it
off.
3. Put the rudder to PORT and give the engine
moderate power AHEAD.
Springing or Warping onto a
Dock 2
1. The left rudder will swing the bow out.
2. The power will move the boat ahead until it is
stopped by the mooring line
3. The shortened mooring line will force the hull
into the dock and stop it’s forward motion.
Take It...
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
Try to avoid if possible
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 1
Port 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 2
Port 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.
Turning Around
Green spot is centre
of rotation for this
manoeuvre
Now….
1. Go out and practice, on your own vessel.
2. See the boat handling quiz.