I'm on starboard but sailing back to restart — do I still have right of way?
No. Rule 21.1 overrides the normal right-of-way rules: a boat sailing towards the pre-start side of the starting line after her starting signal must keep clear of every boat that has started. Being on starboard tack buys you nothing — the moment you turn back towards the line, the starboard advantage disappears and the boats racing hold their course.
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