-
IALA A vs B
- B: USA, South America, Japan, Philippines
- A: Everyone else
-
Preferred Channel Buoys
- Preferred to Port: Red with green band
- Preferred to Starboard: Green with Red Band
- "Preferred to" means keep it on that side of you
- *Examples assume IALA B*
-
North Cardinal Mark N/S
- Black Above Yellow (N) / Black cones point up
- Black below Yellow (S) / Black Cones point down
-
East Cardinal Mark
- Black with yellow band
- Up/Down Arrows
-
West Cardinal Mark
- Yellow with black band
- Arrow apexes together
-
Cardinal Buoy light colors
white
-
Isolated danger buoy
- Black with one ore more red bands
- Ball/Ball topmark
- White light
-
Safe water mark
- Red w/ white vertical stripes
- Single red sphere topmark
- white light
-
Special Mark
- Yellow
- Single X Shape
- Yellow light
-
North Cardinal Mark Lighting Flashes
- Quick (at least 50 flashes)
- or Very Quick (at least 80 flashes)
-
East Cardinal Mark Flashes
- Quick (3) every 10 seconds
- or Very Quick (3) every 5 seconds
-
South Cardinal Mark Flashes
- Very Quick (6) + long flash every 10 seconds
- Quick Flashing (6) + long flash every 15 seconds
-
West Cardinal Mark Flashes
- Very quick flashing (9) every 10 secs
- or Quick flashing (9) every 15 secs
-
Safe Water Mark Flashes
- White Isophase occulting
- Long flash every 10 seconds
- Morse "A" ( . __ )
-
LCS-2 carries ___ shot of chain, ____ shot of wire
- 1/2 shot of chain
- 12 shots of wire
-
-
VLCC vs ULCC
Very Large or Ultra Large Crewed Carrier
-
Plimsoll Mark
Lowest you can load ship in summer
-
TF/F/T/S/W/WNA lines
- Tropical Freshwater
- Freshwater
- Tropical Load
- Summer
- Winter
- Winter N. Atlantic
-
Publication for researching Navy ports
Fleet Guides
-
Fluxgate
- Measures horizontal component of earth magnetic field
- Also subject to variation and deviation
-
-
1 minute of latitude =
- 1 nautical mile
- Degree = 60 "minutes"
-
Types of Charts
- Standard
- Strip
- Cruising/Specialty
- Chart Books
-
On what charts are great circles straight lines?
Oblique Mercator
-
On what lines are rhumb lines straight lines?
Mercator
-
Chart with true shape of physical features
perspective
-
Chart with correct angular relationships
conforming
-
Radar range of pillar buoy
- 3-4 miles, depending on radar/sea return
- Cans/nuns: 1-2 miles
-
RACON on buoy increases radar range of buoy to
6-8 miles or more
-
Lateral marks: WR preceding number
wreck
-
Lateral Marks: Numbers will ___ as you move in sea
- Increase
- Will not necessarily go in exact sequential order
-
Nominal range of a light on normal sized buoy
3.8 miles
-
"Flashing"
Not more than 30 flashes per minute
-
"Quick Flashing"
- Not more than 60 flashes per minute
- Red/Green/or Yellow
-
"Very Quick Flashing"
- 80-160 flashes per minute
- Usually indicates a turn a head or some other attention grabbing thing
-
whistle buoys activated by
wave action
-
Horn buoy activated by
- electricity
- usually better where calm
-
Isolated danger mark flashes
Group flashing (2)
-
Emergency wreck marking buoy
- Yellow/Blue vertical stripes
- blue/yellow 1 second flashes with .5 second interval
- pillar or spar
-
One knot of current has approximately same effect as
30 knots of wind
-
SART
- SAR Transponder
- Will only respond to an X-Band (3 cm wavelength) radar
-
Increase in dew point is increase
in energy available for storm formation
-
standard atmospheric pressure
- 1013.25 mb
- 29.92 Hg
- 14.7 psi
-
Dry adiabatic lapse rate
5.5 degrees F per 1000 ft of altitude change
-
Fog forms when difference between temp and dew point is generally less than
- 2.5 C or 4 F
- More comment when temp of air is around 5 C or 40 F
-
There are ___ NAVAREA's with ____ broadcasts by NGA
- 21 NAVAREAs
- Weekly broadcasts
-
Isogonic Lines
- Equal Lines of variation
- Distance between each line is variation
-
"Stand"
Point where vertical movement of water has stopped
-
Safe Water Mark: "MILO"
- Morse Code Alpha ( dot dash )
- Isophase (Same time on as off)
- Long Flash (10 seconds)
- Occulting (More on than off)
-
"Returning"
- Moving from big water to smaller water
- Proceeding south around an island or landmass
-
How does GPS work?
- GPS sends time
- Time delay used to return posit
- 3x of this issued to fix a position
-
Differential GPS
Ground Based
-
WAAS
- Wide Area Augmented System
- Satellite-Based
-
Luminous vs Nominal Range
- Luminous: Range of visibility under current conditions
- Nominal: Maximum distance it can be sighted during 10 nm of visiblity
-
-
A great circle is a straight line on a
Gnomonic Projection
-
Every fix must have a DR track
projected ahead 2 intervals
-
Estimated fix
- only has 2 LOP's
- Is marked as a square
-
Running Fix
Single LOP DR'ed out
-
Set vs Drift
- Set = Direction
- Drift = Speed
-
Measuring height under a bridge
Measured from mean high water to lowest part of bridge
-
Deviation vs Variation
- Deviation: Caused by ship's magnetic field
- Variation: Caused by Earth's magnetic field
-
Digits: Lat vs Long
- Lat has 2 digits
- Lon has 3 digits
-
Tangent Circle on a transverse mercator
is on a meridian of longitude
-
Mercator projection accuracy
usually within 10 degrees
-
NAVAREA IV / XII distress messages
handled by USCG, not NGA
-
Summary of all broadcast warning and special warning in past 24-72 hrs
Daily Memorandum
-
Navigational warning system outside NAVAREA IV and XII
HYDROPAC/HYDROLANT
-
NTM Broadcasts
- Broadcast by USCG
- Channel 22A and 16
-
Local notice to mariners (LNM)
- Published by USCG weekly
- Like NTM, but more coastal and broken up by USCG district
-
US Notice to Mariners (NTM)
- Published by NGA weekly
- Provides corrections for unclassified nautical charts
-
Satellite Compass
measures phase difference of satellites
-
-
Sailing Directions
- International waters
- Published by NGA
-
-
Fundamental document establishing standards of navigational accuracy
NAVDORM
-
Restricted Waters
- less than 2nm from land
- FOM <= 2
- 3 min fixes
-
Piloting Waters
- 2-10 nm
- FOM <= 4
- 3-15 minute fixes
-
Coastal Waters
- 10-30nm
- FOM <= 6
- 15 - 30 min fixes as conditions warrant
-
Open Ocean
- >30 nm
- FROM <= 7
- 30 min fixes or as conditions warrant
-
"Heave Around to Short Stay"
Heave in on chain until it is vertical but anchor is still embedded in bottom"
-
Walk the anchor out
if the depth > 100 ft
-
Anchor is ready for letting go
Brake is disconnected, all but one stopper removed, weight of anchor hanging on remaining stopper
-
Anchor at short stay
Chain vertical, anchor still embedded
-
Anchor is up and down
Anchor has broken ground, still resting on bottom
-
Anchor is secure for sea
Anchor is housed and stoppers passed
-
How to tell if dragging anchor
- GPS anchor watch alarm
- Anchor chain surging
-
Recommended anchor chain vs depth
5-7 times water depth
-
Swing circle
From anchor to stem of ship
-
Drag circle
from anchor to whatever sensor used to determine if ship is dragging
-
Check vs Hold
- Check: Hold until taut
- Hold: Hold until part
-
Best anchor bottom vs worst
- Best: Firm sand
- Worst: Hard bottom
-
Spectra vs Kevlar
- Spectra is 40% stronger and floats
- Breaking strength of 1/4" line is 8k lbs
-
"Double Braided"
Has a core
-
-
Isolated danger lighting
white light/group flashing (2)
-
Bridge: Green lights
- Mark centerline of navigable channel
- Red lights mark ends of span
-
Info regarding lighthouses
-
Geographic range
- Function of height of light and observer's eye
- Sqrt 1.17 * height of light
-
Regulatory Mark: Diamond
Danger
-
Regulatory Mark: Restricted Ops
Circle
-
Regulatory Mark: Diamond with cross
Exclusion area
-
Regulatory Mark: Square
Information
-
MRASS
- Marine Radio Activated Sound Signal
- click 5x on VHF on 81a or 83a
-
Tidal Day
- 1 high and 1 low tide a day
- 24 hrs and 50 mins
-
semidurnal tides
- 2 highs and 2 lows
- 6hrs 12 mins between them
-
Spring tides
- Increased range, higher highs and lower lows
- New moon or full moon
-
Neap tide
Tide is decreased range nad occurs when moon is half
-
Datum (Tide)
Difference between heights of a given high and subsequent low tide
-
slack water
when horizontal movement of water stops
-
MLW
Mean of all low waters in a 19 year period
-
MHW
Mean of all high waters in a 19 year period
-
DSC vs VHF
- DSC is part of GMDSS
- DSC has distress signals
- DSC can call a specific ship
-
BTB Channel 13
- For passing, etc.
- Must be monitored
-
-
-
NUC
Not able to comply due to "exceptional circumstance"
-
Where can you find a demarcation line?
- Coastal pilots
- chart
- back of colregs
-
You are overtaking if
more than 22.5 degrees abaft beam
-
Sailing rules: Stay out of way
- Wind on Port Side
- Downwind
- Unsure
-
-
-
-
COLREGS: ___ . .
- "D"
- U/W at anchor + RAM
- Difficulty Maneuvering
-
-
COLREGS: At Anchor
- Rapid ringing of bell for 5 secs / 1 min interval
- + 5 seconds gong if > 100 m
-
Troposphere
- Bottom 8 miles of atmosphere
- Temperature drops quickly as you ascend
-
Cooling with increased altitude
- Lapse Rate
- Standard: 3.6 F per 1000'
-
Relationship between water and energy
- More water vapor in air, air becomes lighter
- More water in air, more energy air can carry
-
Relationship between heat and water vapor
- Hotter air can carry more water vapor
- (more water vapor can carry more energy)
-
Relative Humidity
- How much tendency there is for water vapor to condensate in atmosphere at current temperature.
- Measured in percent
-
Dew Point
- Temperature where particular air we are looking at would reach saturation.
- Increase in dew point is increase in available energy
-
Standard atmospheric pressure
- 1013.25 mb
- 29.92" Hg
- 14.7 psi
-
Humidity in atmosphere measured using
- Hygrometer
- Most common type is a psychrometer
-
Isobars are usually spaced
- 4 mb apart
- These are lines of equal atmospheric pressure
-
Drop of 1mb/hr
is pretty bad
-
Change in pressure over time
tendency
-
Dry Adiabatic Lapse Rate
- 5.5 F per 1000' of altitude change
- Specific to dry air rising or falling
-
Saturated adiabiatic lapse rate
- 3.2 F per 1000' of altitude change
- Applies to saturated (100% humidity) air
-
Warm air vs Cold air with water
- Warm air can carry a lot of water
- Cold air cannot
-
Reasons air might move upward
- Convective heating
- Cold air meeting warm air
- Air meeting with a mountain range
-
High, thin clouds developing in wisps/patches
-
-
Advection Fog
- Moist air passing over a cool surface
- California
-
Horizontal Movement of air
-
Wind measured using
anemometer
-
Isobar
Lines of equal pressure with 4mb separation
-
Wind which follows isobars perfectly
- Geostrophic wind
- aka Gradient Wind
-
Determine wind direction at surface using isobars
- Cross isobars at 90 degrees from high to low
- curve 70 degrees to right (N. Hemisphere)
-
Different reflectivity on earth's surface
Albedo
-
Movement of energy through air vs water
- Air moves 60% of energy
- Ocean moves 40%
-
Convection
hot air becomes lighter than surrounding air and rises
-
Region of rising air at equator
- Intertropical Convergence Zone (ITCZ)
- Doldrums
-
Horse Latitudes
- Descending air around the 30 degree mark
- Air moved here via hadley cell
- Results in trade winds/prevailing westerlies
-
Air rising at 60's cycling back toward equator at high altitude
Ferrel Cell
-
Winds blowing outward from poles
- Polar northeasterlies (arctic)
- Polar Southeasterlies (antarctic)
-
Wind blowing along an isobar
Geostrophic
-
Along a front, isobars tend to ____ away from low pressure areas
- Kink
- This creates a wind shift
-
Veering vs backing wind
- Veering wind shifts to right (CW)
- Backing wind shift to left (CCW)
-
Cold front characteristics
- Rapid drop in dew point
- Air is getting dryer
-
Occluded front
- Purple in color
- 3 distinct masses of air
- cold font overtakes a warm front, wedges it aloft
-
Stages of cyclonic weather
- 1. Stationary front
- 2. Cold front overtakes warm front
- 3. Occluded front dissolves, leaving extratropical cyclonic low
-
SW Pacific Hurricane / Indian Ocean
Cyclone
-
NW Pacific Hurricane
Typhoon
-
Buys-Ballots law memory aid
Back to the breeze, low to your left
-
Anti-Cyclones
- High pressure systems rotating in opposite direction as lows
- CW rotation in N. Hemisphere
- Move west -> east
- Blow out and away from high pressure systems
-
Significant Wave Height
Average of highest 1/3 wave height
-
Thunderstorms require 3 ingredients for formation
- 1. Moisture
- 2. Instability
- 3. Lifting Mechanism
-
Air mass thunderstorms
- form as part of single convective cell over hot land or water
- Convection provides lift mechanism
-
Squall lines
- Can generate their own lift
- Have shelf clouds and gust fronts
-
Waterspouts
- Can be fair weather or tornadic
- Speeds 50-60 pmh
-
Fetch
Distance over water which wind blows
-
Vessel Being Towed
- Sidelights & Sternlight
- If being pushed ahead: Just sidelights
-
Towing Vessel
- 2x masthead lights in vertical line
- If tow > 200m, 3x masthead lights + diamonds
- Sidelights/Sternlight
- Towlight
-
Partly submerged objects being towed
- <25m breadth: 360 white light at each end
- >25m breadth: 2x additional white lights at each extremity
- >100m length: white lights so distance between them doesn't exceed 100m
-
Dracones being towed
do not need to exhibit a light at forward end
-
Vessel being towed alongside
sidelights + sternlight
-
Special Flashing Light use
- 50-70 flashes/minute
- Inland towing alongside/pushing ahead
- Placed as far forward as possible
-
SART on RADAR
Shows up as 12 dots
-
Refraction
- Waves change direction as they pass from medium of one density to medium of different density
- Waves will bend toward denser medium
-
Increased downward bending of waves as they travel through atmosphere along surface of earth
Super refraction
-
Slight upward bend/decreased downward bend of waves as they travel through atmosphere
Subrefraction
-
Highly refractive layer in atmosphere resulting in radar pulse ricocheting between surface of ocean and bottom of layer
- Extra super refraction
- aka Ducting
-
Waves changing direction/bending as they pass through an opening or around a barrier
Diffraction
-
Attenuation
Tendency of radar energy to dissipate without returning to receiver
-
TR Tube
- Disconnects receiver
- ATR tube disconnects transmitter
-
Advantages of slotted waveguide antenna
- Low cost
- Less wind exposure
-
Factors affecting radar presentation/interpretation
- Frequency of pulse
- Power
- Shape of pulse
- Pulse length/duration
-
Primary determinant in range resolution/accuracy
Pulse Length
-
3 cm vs 10 cm
- 3 cm most common, not good for heavy rain/sea
- 10 cm less clear, but good for heavy sea/rain
-
Range vs pulse length (PL)
- Short range = Short PL
- Long range = Long PL
-
Range Resolution
ability of radar to separate two contacts on same bearing with slightly different range
-
_____ PL gives better range reoslution
Short
-
Range Accuracy
- ability to measure range to a contact
- Usually about half of pulse length
-
Long PL
Ability to see smaller contacts further out
-
Horizontal beam width
Generally about one degree
-
The _____ the antenna, the _____ the horizontal beam width
Longer, narrower
-
Indirect echo
Appears on other side of an obstruction
-
Fresnel Zones
- Caused by slight difference in phase as pulse travels to target by different paths
- Makes contacts disappear
-
STC
- Sensitivity Time Control
- Decreases radar sensitivity near center of screen
-
FTC
- Fast time constant
- Decreases sensitivity at edges of contact
-
RACON on RADAR
always begins with a dash
-
ARPA
- Auto RADAR Plotting Aid
- Requires 1-3 mins of steady state tracking
- Up to 90% accurate
-
Operational ARPA Alarms
- CPA
- Lost Target
- Target overlap
-
CPA Alarm
- Only goes off if both range and time criteria will be violated
- You set the criteria
-
-
LCS-2 Draft
- 14 ft
- 19.7 ft with AZI deployed
-
LCS-2 Displacement
3071 tons
-
LCS-2 LOA
- 419 ft
- (424 ft specifically on IND)
-
High speed defined by USCG
30kts
-
IMO Froude Formula
Depends on displacement, determines compliance w/high speed code
-
Newton's 3rd Law
Every action has equal/opposite reaction
-
Hydraulic RAM's
- 3x on each bucket
- 2 for steering, 1 for backing
-
Stator vanes (shaft)
Structurally support aft end of shaft
-
LCS-2 Speed max with AZI down
-
-
-
4L
All controls slaved to one
-
Under keel clearance
- Keep 6ft below keel
- Keep 12 ft below jets
-
Transverse Wave
follows behind a ship
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