Cardinal Marks

A cardinal mark is a sea mark used to indicate the position of a hazard and the direction of safe water.

Navigation Lights

To avoid collisions, vessels mount navigation lights that permit other vessels to determine the type and relative angle of a vessel, and thus decide if there is a danger of collision.
In general sailing vessels carry green light on the starboard side, a red light on the port side and a white light that shines from astern. Powerboats, in addition must carry either 1 or 2 (depending on length) white masthead lights.

Boating Knots

Bowline Knot is sometimes called the king of knots. It makes a loop that will not jam and cannot slip. Some other often used boating knots are:
(A)-Reef Knot, (B)-Cleat Hitch, (C)-Clove Hitch, (D)-Anchor Hitch, (E)-Figure 8 Knot, (F)-Sheet Bend

International Flags And Pennants
Buoyage System

The IALA Buoyage System ‘A’ covers all of Europe, the Pacific, Africa and the Indian Ocean and its convention when entering a harbour are Red navigation marks to Port and Green navigation marks to Starboard.

Flags of Convenience

Flag of convenience is the business practice of registering a merchant ship in a state different from that of ship’s owners, and flying that state’s civil ensign on the ship.
Ships are registered under flags of convenience to reduce operating costs or avoid the regulations of the owner’s country.