SM hits on an important subtlety here. PTP left out an important detail: On which side of the line did this occur?

If the RC boat in question was the port end of the line (as shown in the diagram), I agree with all above.

If the RC boat in question was the starboard end of the line, then port would not be inside and would have neither mark room not right of way.

Either way, I agree with all above that this is exactly the same as a leeward gate.

Mike