ASA 106 Related Questions Flashcards
“Seamanship”
“The art of sailing, maneuvering, and preserving a ship or a boat in all positions and under all reasonable circumstances”
The luff of a mainsail is attached to the mast either by:
the bolt rope or slugs
Center of Buoyancy vs. Center of Gravity
CoB - locus of forces keeping the boat afloat; CoG - locus of weight pulling the boat down
Most of the force generated by sails is centered just a bit forward of ______. The ____, _____, ____, and ____ convert that force into forward motion
sideways; rudder, keel, dagger boards, skeg
When the mast is ____ to aft, weather helm is _____..
raked; induced/increased;
The downside of too much weather helm
rudder is slowing down boat vs. adding lift forward
The “right” amount of weather helm tug is about ____ degrees
three
At 1/3 of hull speed, there will be ____ waves created by the boat from bow to stern. At 1/2 hull speed, there will be ____. If there is only one, then the boat is near or at its _______ hull speed.
three; two; one
Displacement to length ratio = D/L ratio
Displacement (in long tons) / (.01xLWL)^3
Displacement to length range of values
30 (dinghy) to 350 (heavy cruisers)
Sail area to displacement ration = SA/D
sail area / (displacement)^2/3
Sail area to displacement SA/D range of values
10 - 24+ Conservative cruisers 10-15 Cruiser/racers 16-20 Moderate racing boats 21-23 High performance racers 24 and above
Six S’s of choosing a boat
Strength Seaworthiness Stability Seakindliness Simplicity
The benefit of a smaller cockpit is that during a storm or heavy seas,
less water can be taken aboard
In a fractional mast design, the jib it hoisted…
below the top of the mast.
In a masthead rig, the jib is usually…
a genoa whose foot extends well into the area of the mainsail
Another name for close-hauled
Beating
Name points of sail from bow to stern (six of them, seven if you remember 1a)
- No-Go Zone 1a. Forereach 2. Close-hauled / Beating 3. Close reach 4. Beam reach 5. Broad reach 6. Running
Deck communication during a tack
“Ready about” “Ready” “Helm’s a-lee”
Deck communication during a jib
“Stand by to jibe” “Ready” “Jibe-ho”
Quick stop method of MOB
Mainsail to the centerline; circles, allowing boat to tack and jibe
Reach and Reach method of MOB
Broad reach for six seconds, tack, head downwind past MOB, turn upwind to MOB
Before casting off, file a ____ _____.
Float plan.
Before casting off checklist (SDSRI)
- Secured boat (battened down inside) 2. Dry boat (check and empty bilge) 3. Safe boat (5 safety equipment items - PDFs, Fire, Flares, Sound, MOB, VHF on/tuned) 4. Ready boat (fuel, water, batteries, cooling; lines; departure plan) 5. Informed boat (crew briefing: float plan; safety; boat features; roles)
Before casting off checklist nmemonic
SDSRI
What is a gilguy?
To hold halyard off mast when docked (stop the clanging)
What is the name of the name of the line that ties halyards away from a mast
Gilguys
Which increases twist in the mainsail – the main sheet or the traveller?
Main sheet
Easing the main sheet has what effect on twist?
Increases it; spills wind
Mainsheet pulled in, boom goes ___ and ____.
inward and down
Mainsheet eased, boom goes ___ and ____.
outward and up
The primary purpose of the traveller is to…
change the angle of attack of the mainsail
What controls the up and down motions of the boom?
top lift vs. boom vang
What is the aft side of the mainsail called?
The leech
What is the name of the cord running through the aft side of the mainsail?
The leech line or leech cord
Genoas are too big in heavy winds because they produce too much ____ _____.
Side force
Common names given to jibs in descending order of size
Genoa, #1, #2, etc.
What is the difference between draft and camber?
Draft is the depth of the deepest part of the sail. Camber is the relationship of Draft to Sail Foot (so 1 foot : 10 feet, camber is 1:10, or 10%)
Increasing camber increases the sail’s _____. Too much camber risks the wind flow becoming _____ from the leeward side of the sail.
power; detached
On a run, with the mainsheets and boom vang opened up, run a risk of _____ between the sail and the _____
chafe; spreaders
The offset to the Center of Lateral Resistance is the
sails’ Center of Effort
The offset to the sails’ Center of Effort is the
Center of lateral resistance
To test a boat’s balance try steering without the helm. Triming the jib tighter will lead to ____ _____. Trimming the main will lead to _____ _____.
Falling off; heading up
To use sails to steer, do the following two things to head up:
Trim the main, ease the jib
To use sails to steer, do the following two things to head up:
Trim the main, ease the jib
To use sails to steer, do the following to fall off:
Trim the jib, ease the main
If the earth didn’t spin, winds would primarily from the ____ to the _____.
poles to the equator (cold air filling in under warm air)
Because the earth spins, the _____ _____ generally pushes air to the right in the ______ _____ and vice versa.
Coriolis effect; Northern Hemisphere
If prevailing winds and local breezes align, can cause
very strong winds
Which is more variable across the span of a day – land temperature or water temperature
Land temp is more unstable, fluctuating more so than a large body of water
The edges of high and low pressure systems can reinforce one another like the edges of a ____.
Gear
High pressure systems spin
clockwise
Low pressure systems spin
counter clockwise
Which is more dangerous – a cold front or a warm front
A cold front, as it pushes warm humid air higher.
A cold front’s calling card is a mass of dense, towering _____ clouds indicating _____ _____.
cumulus clouds; vertical instability
Warm fronts move at about ____ the speed of a cold front.
half
The dew point is the temperature when
fog will form
Fog forms when damp ____ or ____ air flows across cold water and is chilled to its ___ ____
sea or lake; dew point
Fog needs to be “burned off” by _____ the temperature of the air either by the ____ or a warmer _____.
raising; sun; landmass
Name the following type of fog: warm air flowing over colder water or land; typical heavy fog bank of coastal fog; usually winds < 15 knots
Advection fog
Occurs ahead of warm and occluded fronts, rain falling from rising warm air falls into cooler air.
Frontal Fog
A fog bank, warm air blowing over upwellings of cooler air, like entrance to San Francisco bay
Inversion Fog
Occurs over land, at sunset usually, air with peak humidity brought rapidly down to its dew point.
Radiation Fog
Warm air meeting cold water, occurs at sea
Sea Fog
Seen over rivers and small lakes, early morning cooling air sinking down from hills and valleys to lower ground
Steam Fog
Which is more severe – a weather watch or a warning
Warning. A watch is a statement of possible risk. A warning is a statement of current or imminent events.
Cloud type: highest, least substantial, 45,000 feet and above; wispy and lying at oblique angles
Cirrus
Cloud type: wispy clouds lying in sheets; may drape the sky in a gray haze and cause a halo around the sun
Cirrostratus
Cloud type: barely formed puffy balls, altitude 15-45k feet; usually in large clumps; may look like fish scales; mackerel sky, mackerel sky, not long wet, not long dry
Cirrocumulus
Cloud type: sheets 6k to 23k, thicker, darker and more claustrophobic than higher cirrostratus clouds
Altostratus
Cloud type: grayish white rolls, like cirrocumulus but appear darker, sometimes in layers
Altocumulus
Cloud type: Dark, large puffy balls, compressed layers,
Stratocumulus
Cloud type: less dangerous than cumulonimbus thunderheads; puffy white cotton balls at 6k feet.
Cumulus
Cloud type: dark, tightly packed balls, my churn and tower at 6k feet, if broader at top –> anvil head from violent updraft. Strong winds.
Cumulonimbus Clouds
Cloud type: rain-laden, heavy, low-lying, dark gray blankets, come with warm fronts and northeasters, soggy bases just above earth’s surface
Nimbostratus
What is the shape of a cumuli cloud?
Heaped or in a pile
What is the shape of a stratus cloud?
a sheet or horizontal layer
What is the shape of a cirrus cloud
thread-like, hairy, wispy, curled
What is meant by the prefix nimbus or nimbo in clouds
Rain-bearing
What would be the height of a cloud prefixed by alto
cloud of medium height
What would be the height of a cloud with prefix cirro
High level cloud
Describe a cirrostratus cloud
layered wispy high level cloud
Describe a altocumulus cloud
heaped, ball shaped, medium altitude
Describe a nimbostratus cloud
low level layered cloud with rainfall
Describe a cumulonimbus cloud
Thunderhead, large altitude coverage, rain-bearing
Nimbo indicates
water-bearing
Cirro or cirrus
high altitude >23,000 feet
alto
medium altitude 6500 to 23000 feet
strato or stratus
neither balls nor wispy; formed, gather clouds, horizontal
cumulus
ball shaped
Stratocumuluss
Strato – formed, horizontal
Cumulus – balls
Stratocumulus – formed, horizontal, rolling balls
Buys-Ballot law – If the wind is to your back
low pressure is to your left, high pressure to the right
Good use of stretchy nylon lines
Dock lines, anchor lines
Good use of buoyant polypropelene lines
painters, MOB
Good use of low-stretch Dacron or Kevlar
Sheets and halyards
What are meat hooks?
Frayed wire rope
What are the fearsome five characteristics?
Fitness
Food
Fluids
Fatique (sleep)
Fahrenheit (body temperature)
To avoid seasickness, take medications…
… well before departure
Seasickness treatment Horizon Viewing
Windward side, look ahead at horizon and water without staring, broad peripheral view of the sea, anticipate boat movements, adjust body so torso and head are balanced above hips
Seasickness treatment: Nibbling
sips of water or sports drinks, crackers, cookies, bananas
Cruising boat Medical preparedness considerations
Consideration of length of trip, distance to professional medical services, crew fitness, on-board medical knowledge, communication abilities
Main cause of injury on a boat
Falls
Always hook into the ______ jack line
windward
Precise range of visibility formula
1.144 x sq. root of height (lighthouse, height above water, etc.)
Mark DR plot position (direction and time only) with a _______.
Mark an estimated position (having at least one bearing) with a _______.
Mark a fix two or more bearings with a _____.
half-circle
square
circle
The small triangle formed by three bearing lines nearly intersecting is call a:
If it is a very large one, then
“cocked hat”
throw out the least reliable bearing and chose the point of the triange defined by the other two
In beating, when navigating take the _____ tack first, unless a _____ one will keep you closer to land or fixes.
longest
short
In a running fix, when the bearing angle to a fixed object is doubled (45/90, 30/60, 40/80) the distance off is equal to
the distance sailed between the two readings
