red and green sidelights
A masthead light, side lights and a stern light are the lights that power driven vessels less than 65.6 feet long and underway between sunset and sunrise exhibit.
Power-driven vessels less than 65.6 feet long must exhibit a white masthead light and a white stern light between sunset and sunrise when underway. Additionally, they should also display red and green sidelights when the visibility is restricted.
Rules of the RoadInternational/InlandLights & shapesRule 23-Power-driven vessels underway(a) A power-driven vessel underway shall exhibit:(i) a Masthead light forward;(ii) a second masthead light abaft of and higher than the forward one; except that a vessel of less than 50 meters in length shall not be obliged to exhibit such a light but may do so;(iii) sidelights; and(iv) a stern light*note on side lights. Red is port side (left) and green is starboard side (right)
Power-driven vessels less than 65.6 feet long must exhibit a green light on the starboard side and a red light on the port side, in addition to an all-around white light, when underway between sunset and sunrise. These lights help other vessels determine the direction the vessel is moving and avoid collisions at night.
Rules of the RoadInternational/InlandLights & shapesRule 23-Power-driven vessels underway(a) A power-driven vessel underway shall exhibit:(i) a Masthead light forward;(ii) a second masthead light abaft of and higher than the forward one; except that a vessel of less than 50 meters in length shall not be obliged to exhibit such a light but may do so;(iii) sidelights; and(iv) a stern light*note on side lights. Red is port side (left) and green is starboard side (right)
Port and starboard steaming lights and stern light
When away from the dock after sunset.
When away from the dock after sunset.
When away from the dock after sunset.
Port and starboard running light and stern light.
Various navigation methods were proposed, however some aspects of insect navigation that are not completely understood. Scent trail. Counting steps. Polarised light. etc. Just Google "insect navigation" and read your way around. It is amazing how small their brain is for the skills they exhibit.
Their masses and the distance between them determine the force they exhibit on each other.