What light configuration is used to signal a sailing vessel at night with sidelights?

The configuration that uses sidelights to signal a sailing vessel at night typically involves the use of sidelights in conjunction with a sternlight. Sidelights consist of a green light on the starboard side and a red light on the port side, allowing others to determine the direction the vessel is facing. The addition of a sternlight, which is white and located at the stern, completes the visual signaling by providing information about the vessel's position from behind.

This combination of sidelights and a sternlight is standard for sailing vessels and helps in maintaining safe navigation and visibility, especially during night operations. It enables other vessels to ascertain the sailing vessel's orientation and movement, which is crucial for avoiding collisions.

Other configurations presented, such as having all lights in a single lantern at the top mast or using two red lights, do not conform to the regulations for sailing vessels and would not effectively convey the required information to other vessels. Specifically, the use of two red lights could lead to confusion about the vessel's course. The "green over white" option also does not apply to the typical sailing vessel at night but rather might refer to specific signal lights for other types of vessels or scenarios.