Ship Construction
Define "keel" and "frames"
50+ Bonus: What human body parts are analogous with these parts
Keel: The main longitudinal timber of most hulls, on which the frames and end of the hull are attached. needed for strength and maneuvering weather
Frames: one or more timbers that shape the body of a ship
50+ bonus: the spine (keel) and ribs (frames)
Name the 3 remote sensing methods covered
1. Sub Bottom Profiler
2. Side Scan Sonar
3. Magnetometer
Define "ballast"
heavy material such as iron, stone, bricks, or gravel placed in the hold of the ship to lower center of gravity and add stability when carrying little or no cargo
True or False: Drawing and Illustration are the same thing
False. Illustration is used in professional contexts, can have more commercial value, and is accompanied by text
Name the 2 types of measurements covered
Baseline-Offset and Trilateration
Name the 2 main structures that support steering.
rudder & transom
Which remote sensing method helps find iron anomalies on or buried under the seafloor?
Magnetometer
Why is artifact identification important?
Identifying artifacts can help inform a ship's size, weight, voyage route, trade routes, nation of origin, etc.
Define an 'in situ' illustration
50+ Bonus: True or false: all illustrations are planimetric, viewing from the top looking down
An illustration done with the artifact in it's original place, undisturbed. Underwater, in this case
50+ Bonus: True
True or False: baseline-offset measurements should be used for artifacts that are 10 meters or less from the baseline.
50+ bonus: What angle should the measurement form?
False. Baseline-offset measurements should be used for artifacts that are 3 meters or less from the baseline.
50+ bonus: The measurement should be a straight line from the baseline and form a right angle.
Name 4 different keel units.
any four of the following:
false keel, rider keel, keel, keelson, sister/assistant keelson, rider keelson, rider sister keelson
True or false: side scan sonar helps find anomalies stick out of of laying on the sea floor?
50+ Bonus: How does this instrument work?
True.
50+ bonus: Side scan sonar emits a sound pulse and analyzes the echo to paint an acoustic “picture” of the bottom. It translates two way sound travel time into distance, and strength of return into brightness of an image.
True or false: When pin flagging artifacts you should start furthest from the baseline and move in.
50+ Bonus: How many reference points should each artifact have?
False. You should start closest to the baseline and move out
50+ Bonus: 2
Why illustrate?
Illustration = Communication + Interpretation
illustrations can precisely isolate specific or features of an artifact, omitting irrelevant details and making clear essential attributes.
scientific illustrations can be a more successful form of visual communication than photography.
When performing trilateration, how many measurements are taken for each reference point? What is the ideal shape formed when taking measurements.
2 measurements per reference point. an equilateral triangle
Why is it important to identify timbers?
often, timbers and cargo are all you have left.
timbers help estimate size and shape of ship, nation of origin, time period, etc.
Name 3 Diver Search Techniques
circle search, pendulum pattern, baseline pattern, snag-line pattern, swimline pattern
What does it mean for an object to be concreted?
over time, metal artifacts and some organic items deposited in the sea form a composite crust of marine minerals, corrosion products, sediments, and natural life
What is the correct process for artifact illustration?
1) take measurements
2) record the general shape and outline of artifact
3) capture and record details
4) combine measurements and details into comprehensive drawing
Define "active" and "passive" divers
passive diver: diver holding the 0 end of the tape measure, steadily, at the reference point
active diver: diver at the baseline taking and recording measurements
What is the difference between a raft, boat, and ship?
Rafts simply float, whereas boats and ships displace water. An object that displaces water, aka an object in water, is acted upon by buoyancy equal to the weight of the water displaced. So the more water displaced, the more buoyancy generated.
A diver target dives an anomaly near a shoreline. Which diver search technique would they use?
Pendulum search
What is your responsibility during the reconnaissance dive?
divers will enter the water for the first time and circle the site, making note of key features and artifacts that should be mapped in your section. Consult with neighboring buddy teams if there are artifacts that intersect sections.
Name at least 3 details that should be included in your illustration
reference point numbers and positions, artifact orientation, measurement and dimensions, materials, annotations, etc.
a map where all of the buddy team illustrations are combined and consolidated into a scaled illustration representing the entire wreck site