New Jersey Scuba Diving

United States Coast Guard 2 (1/7)

USCG - Historical Overview

USCG
A boarding party from the Revenue Cutter Morris prepares to board the passenger vessel Benjamin Adams on 16 July 1861 about 200 miles east of New York. The Benjamin Adams was bound for New York from Liverpool and carried 650 Scottish and Irish immigrants. The Revenue Cutter Service was originally established to enforce U.S. laws at sea and inspected incoming merchant vessels for compliance with those laws, as is illustrated here.

The United States Coast Guard is this nation's oldest and its premier maritime agency. The history of the Service is very complicated because it is the amalgamation of five Federal agencies. These agencies, the Revenue Cutter Service, the Lighthouse Service, the Steamboat Inspection Service, the Bureau of Navigation, and the Lifesaving Service, were originally independent, but had overlapping authorities and were Shuffled around the government. They sometimes received new names, and they were all finally united under the umbrella of the Coast Guard. The multiple missions and responsibilities of the modern service are directly tied to this diverse heritage and the magnificent achievements of all of these agencies.

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Light, Air & Water

Human Vision Underwater

When light travels from a less-dense medium like air to a more-dense medium like water, the rays are refracted or bent towards the normal or perpendicular of the surface between the two mediums. In crude terms, light going from air to water will tend to be straightened, while light going from water to air will tend to be ... um ... crookeded. Confused yet? Take a look at the figure below.

refraction
( Tautogolabrus adspesus )

In this figure, you can see the light rays traveling from an object in the water to your eyes, neglecting the effect of the flat glass lens of your mask. The blue lines trace the actual path of the light rays through the water and into the air, or conversely, through the air into the water - the direction really doesn't matter. As you can see, the rays are bent toward the perpendicular of the surface on the water side, and away from it on the air side.

More: Light, Air & Water ...

Disclaimer:

I make no claim as to the accuracy, validity, or appropriateness of any information found in this website. I will not be responsible for the consequences of any action that is based upon information found here. Scuba diving is an adventure sport, and as always, you alone are responsible for your own safety and well being.

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