Miscellaneous


Artifacts recovered after long immersion in salt or freshwater require conservation treatment if they are to last. On exposure to high concentrations of oxygen in the air, iron artifacts will bloom into piles of rust. Wood will crack and split if dried out improperly. Organic materials will crumble to dust.

The manual below details conservation methods for many types of materials and artifacts.


Alpha-Numeric Signal Flags

In this modern age of radio, these signal flags are a quaint anachronism that is no longer used, although they were once very important in ship-to-shore and ship-to-ship communications. Each flag stands for both a letter value and a shorthand message. The letters are expressed here in the modern international phonetic alphabet, in which A-B-C would be spoken Alpha-Bravo-Charlie (see below).


Marine distance measurements are expressed in terms of nautical miles. A nautical mile is significantly different from a common or statute mile. The conversion is 1 nautical mile = 1.151 statute miles, or approximately 6076 ft ( vs. 5280 ft for a statute mile. )

Why such a confounded thing as this? Here's why:


Port & Starboard

port - the left side of a ship, when facing forward

starboard - the right side of a ship, when facing forward

running lights

The starboard side of a vessel ( or an airplane ) carries a green running light, and the port side carries a red running light. The best way to remember all this is: port, left and red are all short words, while starboard, right, and green are all long(er) words.


Shipwreck Iberia
Iberia struck by Umbria

How do two ships in the wide ocean collide? It seems unlikely, and yet it happens all the time. Often, the ocean is not all that wide. Many collisions occur in shipping lanes and port approaches, where ships are brought together in close proximity. Here are some videos of actual collisions between ships:


wire drag
A fine diagram of a wire-drag operation. The wire is towed between two tugboats, suspended by buoys at a predisposed depth. When the cable snags on an obstruction and draws into a V, the buoys point to its location.

Wire dragging is an operation used to locate and/or reduce the navigational hazard of a sunken wreck, rock, or other obstruction.


Muskrat

Ondatra zibethica

Size: to 14" (body)

Habitat: in and around water

Notes:
Muskrats sometimes build a water "house", like a beaver, although they don't build dams. Common anywhere there is suitable watery habitat.

Printed from njscuba.net