1. Instructors: George Crowl
ABL-13
Able
Weather
This PowerPoint is provided for those who may not have appropriate training aids available in a ship or location. This generally follows a companion lesson plan available at I expect you to modify it to fit your situation and teaching style. I am more concerned that Scouts learn than this fit a specific style. I am, however, a fan of the Effective Teaching model. Teaching EDGE is somewhat simplistic in its approach, but that has some advantages.
Note: These lesson plans may also be used for teaching in the ship. For administrative convenience, they cover the entire specific numbered requirement (except one, where Galley is covered separately!). Individual Sea Scout Academy lessons may only cover part of the requirements. Similarly, ships may find that even just a portion of a subrequirement is all that can be done during a particular ship meeting. Adapt these lessons as needed to fit your youth and your situation. Share these plans with your youth who are teaching.
Philosophy: Sea Scout Academy’s primary purpose is to teach the material to the Sea Scout. If the Sea Scout demonstrates mastery of parts of the subject, then the instructor should annotate on the class roster what has been passed, in the instructor’s opinion. Skippers have the right to re-examine any Sea Scout in any requirement. (Knots are not a good subject to give a pass in.) SSA may schedule only portions of ORD-8.
Instructors: George Crowl

2. Course Outline
Demonstrate your ability to read a barometer, thermometer, anemometer, and weather vane. Be familiar with the Beaufort Wind Force Scale.
Requirements:
Reference:

3. Barometer Barometer measures air pressure
Air pressure is an indication of current weather
Air pressure trends are an indication of future weather
Falling barometer = stormy weather
Rising barometer = clearing weather
Steady barometer = steady weather
Many instruments today have digital scales, making reading very easy. However, look at the illustrations in the Sea Scout Manual, which are for analog instruments. The barometer in the PPT reads inches of mercury. You must first interpret between 30 and 31. Both 30.0 and 30.1 are marked. Then, you must look at the scale, which is 0.02 inches, and the needle is about 4/10 of the way from 30.0 to 30.1, or Each analog instrument has its own unique scale, and must be interpreted correctly.

4. Different Barometers Original barometer – mercury
Newest barometer - digital
The original mercury barometer had a scale behind it, measuring the distance above the pool of mercury. Most scales were in millimeters, some in inches. Standard day pressure was 760 mm of mercury, or inches of mercury. A third measure is in millibars, where 750 mm is one bar, or millibars.
The newest digital barometers just read the numbers out directly, so the digital barometer reads inches of mercury. It can be set to express the value in mm or millibars.

5. Different Barometers (2)
Common barometer – aneroid
Has a vacuum cham- ber, moves pointer
30.04” mercury or MB
Hand at 29.00” can be set to track trend
The most common barometer on Sea Scout ships will be the aneroid barometer. It too has a vacuum chamber, which moves in and out, and moves the dial. The one above is calibrated in inches of mercury and in millibars. The reading is 30.04” or 1017 mB. Note also that there is a hand at 29.00”. This hand is settable, to allow the observer to track the trend, in this case a dramatically rising barometer suggesting clearing skies and good weather.

6. Thermometers Outdoor - °C or °F Note scale
Engine – highlights high temperature
Digital – direct reading
The thermometer is the most common instrument. Most US thermometers are in Fahrenheit, becoming more common is Celsius scale, where 0° is freezing and 100° is boiling. Some thermometers are dual scale, some digital can be switched, and some have only one scale. Specialized thermometers such as engine temperature will have markings that help alert the operator to problems, such as red for water temperature over 210°.

7. Anemometer Measures speed (and direction) of wind
Analog, vacuum and digital readouts
Normally shows relative wind direction & speed
Can be tied to GPS to provide true wind dir / vel
Mounted on highest mast
The anemometer measures wind speed. The anemometer on a boat only measures true wind speed when the boat is stopped. Any time the boat is moving, the anemometer will read relative wind speed, in relation to the boat. For instance a boat traveling north at 10K in a south wind of 20K will only show a 10K wind. However, tying that to a GPS will allow a display of true wind. When sailing, relative wind is actually more important.

8. Wind Vane Shows relative wind Little red tabs show “eye of the wind”
Does not show velocity unless anemometer is tied into it
Does not show true wind direction
Mounted on highest mast
The wind vane, often a combination wind vane and anemometer, also only measures true wind direction when the boat is stopped. Otherwise, it too measures relative direction. This is very useful in sailing, because the sails react to the relative wind. It is somewhat less useful for weather forcasting.

9. Beaufort Wind Scale
Invented by British Admiral Francis Beaufort in 1805
Designed for open ocean, bay or lake will be less accurate
Relates wind speed (K) to sea state to wind names
Is still the basis of small craft warnings, gale warnings, storm warnings, etc
Force 5, 16-21K, “Fresh Breeze,” is usually the limit for Sea Scout sailing
The Beaufort Scale regularized wind observations at sea in the early 1800s. It was correlated with wind speeds in the early 1900s. It is designed for the open ocean, so observations on a bay or lake are likely to produce a lower figure for a given wind speed. Sailboats are usually more comfortable in Force 3 winds, and probably should not go out in Force 5 or higher. “Be familiar with” means that you should be able to compare your observation with a copy of the chart and identify the current Force of the wind, and translate that to approximate miles per hour or knots.

10. Beaufort Scale L A

11. Questions? R