Next we are looking at a vessel that is in the process of DREDGING or participating in an UNDERWATER operation as shown here.

As you will note it has MANY lights while in operation! Sidelights, stern light, double vertical round RED lights on the extended STARBOARD (RIGHT) side designating where the obstruction is located, two vertical round GREEN lights used to designate which side a vessel may pass on (PORT or LEFT side) and the WHITE and RED alternating set of vertical lights.

The shapes you see in the photo are used in as follows: the two BLACK vertical BALLS where the obstruction is located and the two BLACK vertical DIAMONDS to designate the side to pass.

Hugh Simpson