102 NAVIGATION FUNDAMENTALS Flashcards
Describe the effects of SEA, WIND and Current on small boats
can make the small boats go off course
How does CAVITATION affects small boat handeling?
Propeller draws in an air water mixture causing LOSS of EFFECTIVE THRUST and propeller EFFICIENCY
what is IALA systems A and B?
- International Association of Lighthouse Authorities.
- Standard system of Buoys used around the world
- A = Asia, Africa, Europe (green right returning)
- B = The Americas and Japan (red right returning)
what is High Tide?
MAX water height from the RISING tide
What is Low Tide
MIN water height from the OUTGOING tide
What actions should be taken by the Give Way and Stand-On vessels in a OVERTAKING situation?
- Stand on Vessel must keep out of the way of the vessel being overtaken
- Give way vessel can’t turn and cause crossing situation
Define Mean High Water
Average height of all HIGH-Tide water levels, measured over a 19-year period
Define Mean Low Water
Average height of all LOW-tide levels, observed over a 19-year period
Define Spring Tide
Tides that occur when SUN AND MOON IN LINE WITH EARTH, causes HIGH tides to be HIGHER and LOW tides to be LOWER
Define Compass Bearing
The direction you are headed, as shown by a compass
Define Fix
Known Point on Earth
Define Relative Bearing
Direction from the boats bow at 000⁰, measured clockwise through 360⁰
Define Dead Reckoning
The process of calculating one’s position, by estimating the direction and distance rather than using wind, sea conditions and sea current
How do you determine a safe speed in a STATE OF VISIBILITY
as visibility decreases, boat speed should also decrease
How do you determine a safe speed in a TRAFFIC DENSITY
Alot of traffic density requires slower speed to avoid collision
How do you determine a safe speed for a STOPPING DISTANCE AND TURNING ABILITY?
Faster speed increase stopping distance required
Slow speed when making sharp turns so that you do not overshoot your turn
How do you determine a safe speed at NIGHT?
Decrease speed at night in order to readily recognize other vessels and buoys
How do you determine a safe speed in a WIND, SEA AND CURRENT?
More RPMs may be required to fight resistance. More control is required when mooring
How do you determine a safe speed with LIMITATIONS OF THE RADAR EQUIPMENT?
Requires slower speed and lookouts to be more alert
How do you determine a safe speed with EFFECTS ON RADAR DETECTION OF THE SEA STATE WEATHER?
vessel speed should be reduced when interference caused by sea state of weather impairs the performance of the radar
How do you determine a safe speed WITH ICE AND OTHER FLOATING OBJECTS THAT MAY NOT BE DETECTED BY RADAR?
requires slower speed and lookouts to be more alert
Define Line of Positioning
A line of Bearing (direction) to a known object, which a vessel is presumed to be located on at some point
Define Slack Water
The period of time where there is LITTLE OR NO CURRENT
Define EBB current
Horizontal movement of water is AWAY FROM SHORE
Define Flood Current
Horizontal movement of water is TOWARD SHORE
How far is a Nautical mile in yards?
2000 yards
What is a Target Angle?
The relative bearing of your ship from another ship
What does 5 short blasts mean?
General duress including man overboard
What does 3 short blasts mean?
Astern propulsion
