Boat Operations

Question 1

Set

Answer 1

Direction toward which water is flowing, measures in True degrees

Question 2

Drift

Answer 2

Current, wind, and waves measured in knots

Question 3

Windward

Answer 3

Side of direction from which the wind is blowing

Question 4

Leeward

Answer 4

Side or direction away from the wind

Question 5

Pitching

Answer 5

Up/down motion of bow/stern

Question 6

Rolling

Answer 6

Side to side motion

Question 7

Yawing

Answer 7

The boat sheering off to port or starboard due to the action of waves taking charge of the stern and may cause to broach.

Question 8

Flooding tide

Answer 8

Tidal current flowing from sea toward the shore, resulting in higher tidal stages

Question 9

Ebb tide

Answer 9

Tidal current flowing from shore to sea, results in lower tidal stages

Question 10

Slack tide

Answer 10

The period of no horizontal movement

Question 11

Eddy current

Answer 11

Occurs at channel bends, uneven bottoms and near points of land. A circular current

Question 12

Center of gravity

Answer 12

Point at which the weight of the boat acts vertically downwards

Question 13

Buoyancy

Answer 13

The upward force of water displaced by the hull. Force of buoyancy keeps boat afloat.

Question 14

Center of buoyancy

Answer 14

Center of gravity of displaced water.

Question 15

Equilibrium

Answer 15

Center of buoyancy acting upwards/vertically is below the center of gravity acting downwards.

Question 16

Heeling

Answer 16

Temporary leaning

Question 17

Listing

Answer 17

Permanent leaning

Question 18

Tripping

Answer 18

When a boat is pulled sideways by an opposing force. Can cause the boat to heel over beyond its ability to right itself

Question 19

Two types of stability

Answer 19

Longitudinal (fore and aft) prevents pitching

Transverse (athrwatship) prevents capsizing

Question 20

Two primary forces of stability

Answer 20

Static- inside forces

Dynamic- outside forces

Question 21

Free surface effect

Answer 21

Vessel containing liquid in a compartment. The liquid can flow from side to side which makes the boat not want to right itself. This causes loss of stability

Question 22

Free communication with the sea

Answer 22

Unobstructed movement of seawater into and out of a vessel due to damage of the hull.

Question 23

Downflooding

Answer 23

The entry of water into the hull, due to lack of maintaining watertight integrity of a vessel.

Question 24

Barometric pressure

Answer 24

Normal: 29.92

Dropping will cause warmer, cloudier weather. Continually decreseasing will cause weather to worsen.

Question 25

Surf

Answer 25

Lines of waves that mount higher as they pass over shallower water and finally break as they near the beach.

Question 26

Breaker

Answer 26

A wave or swell of the sea breaking on the shore, shoal, reef bar or inlet.

Question 27

Window

Answer 27

Area where waves have momentarily stopped breaking

Question 28

High/low side of wave

Answer 28

High- carries most potential energy Low- least potential energy and represents the safest direction to turn

Question 29

Saddle

Answer 29

Lowest part of wave

Question 30

Closeouts

Answer 30

Two waves breaking towards each other. Should be avoided

Question 31

Shoulder

Answer 31

The edge of a wave

Question 32

Rip current

Answer 32

A relatively strong, narrow current flowing outward from the beach through the surf zone and presenting a hazard to swimmers

Question 33

Chine

Answer 33

The edge formed on the hull of a flat bottomed or V shaped boat where the bottom joins the topside.

Question 34

Hard chine lockup

Answer 34

Boat suddenly heeling 50-80 degrees on a false keel. Must turn into direction of heel and immediately back to amidships to rock MLB off it's false keel.

Question 35

Types of breaking waves

Answer 35

Plunging Spilling surging

Question 36

Surf

Answer 36

Several waves or swells of the sea breaking on the shore, shoal, reef, bar, or inlet

Question 37

Swell

Answer 37

Distant wind generated waves which have advanced to calmer and more rounder form. The heave of the sea.

Question 38

Wave

Answer 38

A periodic disturbance of the sea caused by local winds

Question 39

Plunging

Answer 39

Lack of water ahead of the wave. Raises up suddenly and breaks with tremendous force.

Question 40

Spilling

Answer 40

Generated when the ocean floor has a gentle slope, gradually spills forward down its face until it is all whitewater.

Question 41

Surging

Answer 41

Wave builds very quickly and expands its anger on the beach

Question 42

Pitch

Answer 42

Distance a propeller would travel in 1 revolution

Question 43

Cavitation

Answer 43

the formation of bubbles in a liquid, caused by low pressure in the suction intake by the movement of a propeller. This creates less pressure. Resulting in lest thrust.

Question 44

Side force/ prop walk

Answer 44

Stern moves sideways due to unequal blade thrust.