Final answer:
Leave the half red half white buoy on the starboard side when returning from seaward in US waters, adhering to the 'red, right, return' navigation rule.
Step-by-step explanation:
When returning from seaward in US waters, you should leave the buoy with the red and white color scheme on the starboard (right) side of your boat. This color configuration typically indicates a safe passage on the starboard side when following the conventional direction of buoyage in the United States, also known as the 'red, right, return' rule. It implies that as you return, or head upstream, from the open sea towards port, all red marks should be kept on the starboard side of the vessel to ensure correct navigation through channels and past hazards.
When returning from seaward in US waters, you should leave the half red half white buoy on the right side of your boat. This is known as the starboard side. In the US, buoys and other navigational aids follow the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) System A, which means that red buoys mark the port (left) side of the channel when entering from seaward and white buoys mark the starboard (right) side of the channel.