The best way to pass boats when rounding a leeward mark to port is to do a Mexican takedown. The Mexican allows you to carry the spinnaker right into the rounding while also preventing the sail from falling into the water. You’ll be the inside right-of-way boat, entitled to mark room over boats doing leeward takedowns. Here’s how to do it:

Going into the turn, the spinnaker is over trimmed pulling the foot right up to the deck. As the driver does the smooth left turn, this well-choreographed sailing ballet results in the spinnaker inverting and now laying on the new windward side of the jib. Here are the “steps:”

1. The bow team grabs the foot of the spinnaker as it collapses onto the windward side of the jib, 
2. The pit person smokes the halyard,
3. As the sail slides down the jib onto the deck, the bow team gathers it in,
4. The pit person then blows the tack line, and 
5. The sail gets stuffed down the forward hatch with at least three quarters of the sail on the deck before going upwind.

UK Sailmakers Transcript on Youtube

How To Do a Mexican Takedown Also Called the Kiwi Drop