SEAMANSHIP CH. 5 BOAT HANDLING

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SEAMANSHIP CH. 5BOAT HANDLING
REFERENCES Chapmans Chapter 6 and AUX study
guide
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RESPONDING TO PHYSICS

1. Discovering the relationship between the laws of
   physics and boat behavior can be perplexing.
2. No two boats respond the same even under
   identical circumstances.
3. Successful boat handling requires practice.

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HELMSMANSHIP

1. The ability to steer well.
2. Cannot be mastered from a book or in a classroom.
3. Involves your reaction - response to the entire
   boat and its total environment including the
   weather.
4. You must attain the basics of performance from
   hands on experience in order to fully
   understand and master the helm.

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GOOD HELMSMANSHIP

1. Know Your Boat
2. Take it easy on anothers boat until you get the
   feel and know their boat.
3. Out of sight of land use compass and keep lubbers
   line on the course to be steered.
4. Near shore use landmarks

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BASIC TERMINOLOGYINBOARD OUTBOARD I/O THRUST
PROPELLER

1. INBOARD Engine mounted within the hull
2. OUTBOARD Engine mounted on the transom and
   detachable.
3. I/O Combination of inside and outside.
4. THRUST Force moving the boat through the water,
   gained by a propeller.
5. PROPELLER A screw which, when rotating. draws
   in water from ahead and pushes it out astern

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TERMINOLOGY ContdSINGLE/TWIN SCREW AUXILIARY
INBOARD OUTBOARD

1. SINGLE SCREW Boat with one propeller
2. TWIN SCREW Boat with two propellers.
3. AUXILIARY Sailboat fitted with an engine
4. INBOARD Fixed direction of thrust, only changed
   by rudder action.
5. OUTBOARD OR I/O Direction of thrust is changed
   by rotating the engine. Change of direction of
   thrust is the rudder.

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TERMINOLOGY ContdSTEERING 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.

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TERMINOLOGY ContdHEADWAY STERNWAY
TURNINGRIGHT/LEFT RUDDER

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.
5. RIGHT OR LEFT RUDDER Direction the bow turns
   to.

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TERMINOLOGY ContdRIGHT/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 on
  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.

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SCREW CURRENT

• 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.
• RUDDER(S) are ONLY EFFECTIVE, when the boat moves
  through the water.

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LEFT HAND / RIGHT HAND PROPELLERS
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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.
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EFFECT OF TORQUE BY SINGLE SCREW

• 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.

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HANDLING CHARACTERISTICSPLANING Vs. DISPLACEMENT
HULLS

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.

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HANDLING ContdWINDCURRENT Vs. HULL TYPES

1. HANDLING ALL HULLS 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

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HANDLING ContdEXPOSED HULL AREA Vs. WIND
DRAFT CURRENT

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.

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TURNING THE RUDDER OR ENGINE
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MANEUVERING TWIN SCREW BOAT
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MANEUVERING WITH DIRECT THRUSTOutboard and I/O
1. The boat is maneuvered by directing the
propeller thrust. There is no rudder. 2. Directed
propeller thrust makes slow speed maneuvering
easier. 3. Normal or high speed turns are
sharper. 4. May not respond well when there is no
thrust. 5. While reversing, propwalk of reversing
propeller tends to throw the stern to port, but
to a lesser extent than inboard craft.
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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

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MOORING LINES
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No Wind Or Current
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Close Quarters
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Wind Or CurrentOff Dock

• Use sharp angle of approach
• Secure after spring line
• Apply power and use steering control to bring
  stern to dock
• Go slow

inboard
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Casting Off Wind On Dock

• Release stern line
• Place fenders
• Shift into forward
• Release bow line after stern is clear

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2
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9/8/2020
Ted Potter DCAPT/SHR
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Casting Off Wind Off Dock

• Release all lines
• Push boat away from dock
• Shift into forward and depart

3
2
1
9/8/2020
Ted Potter DCAPT/SHR
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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

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REVIEW QUESTIONS

• The part of the current that flows into the
  propeller is called the ____ ____ ____
• c. suction screw current

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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
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REVIEW QUESTIONS
2. When a right handed propeller is turning
clockwise, the boat will go_________ a.
forward
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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
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REVIEW QUESTIONS
3. The stern of a single screw boat with a left
handed propeller tends to go_______________ when
the propeller is reversing. a. to starboard
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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
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REVIEW QUESTIONS
4. When the rudder is put over, the stern is
_________ the direction the rudder moves. b.
kicked away from
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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
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REVIEW QUESTIONS
5. When backing a single screw inboard with a
right hand propeller and rudder amidship, the
stern will ___________ d. move to port
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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
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REVIEW QUESTIONS
6. The mooring line that keeps the boat from
going ahead is the ____ d. after bow spring
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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 its own length c. turn within 1/3 of
its own length d. back easier
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REVIEW QUESTIONS
7. By going ahead on one engine while reversing
the other enables a twin screw vessel
to_____________ b. turn within its own
length
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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
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REVIEW QUESTIONS
8. Getting away from the dock, when the boat is
being set into it by the wind, generally
requires using _______ a. an after bow spring
line
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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
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REVIEW QUESTIONS
9. Breast lines are set____________the boats
hull. c. perpendicular to.
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REVIEW QUESTIONS NO. 10
10. The discharge current of the propeller is
always located on _______ a. the down current
side of the propeller b. the up current side
of the propeller c. behind the propeller d.
ahead of the propeller
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REVIEW QUESTIONS
10. The discharge current of the propeller is
always located on the ____ a. down current
side of the propeller
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END CHAPTER 5