You are looking at the Starboard (right) side of that boat. If it is moving, it is moving to the right.
another vessel is at anchor
The head and starboard side of the vessel is toward you
When boating at night, a single white light on a vessel tells you that it is anchored.
The green light would be the starboard steaming light, the white the masthead light. What you would do would depend on factors such as its releative bearing and in what waters you are sailing.
A sailing vessel under sail at night must exhibit red and green sidelights and an all-round white light when underway. The red light is displayed on the port side, and the green light on the starboard side, while the all-round white light indicates the vessel's presence and helps prevent collisions. This lighting configuration is essential for visibility and safety on the water.
When boating at night a red and white light on a vessel tells you that you must give way to the other vessel.
You are the stand-on vessel but should take precautions in case the other operator doesn't see you.
A commercial vessel towing at night displays a white towing light above the stern of the towing vessel and a second white light at the stern of the tow. Additionally, the vessel should show a green light on the starboard side and a red light on the port side, as well as an all-round white light at the stern of the vessel being towed. These lights help indicate the vessel's activity and ensure safe navigation for other vessels.
During nighttime transit another boat's lights show: Green - the right, or starboard side, of that vessel; Red - the left, or port side, of that vessel; White - the rear of that vessel. The vessel is heading directly toward you
fishing at night
you are on the port side of the vessel
Navigation lights, green starboard and red port. Masthead and stern lights should be white