UPWIND / BEATINGAdvanced

The lee-bow tack

The situation

Crossing on port, Tom decides to tack onto starboard right on the lee bow of an oncoming starboard-tack boat, hoping to slow her and roll over the top. He tacks close ahead and to leeward.

The question

When does Tom actually earn starboard-tack rights, and what's the risk?

The ruling

Not until he is fully on a close-hauled course on starboard. While tacking (from head to wind until close-hauled) rule 13 makes Tom keep clear; if the other boat has to take avoiding action during that window, he's broken rule 13. Even once he completes the tack, rule 15 means he must give her room to keep clear at first. A good lee-bow is completed with room to spare — a late one that forces the other boat to bear away or luff is a foul.

Key point

A lee-bow only works if you complete the tack with room — you have no rights until you're close-hauled (rule 13).

Opens the situation on the boat-length grid — scrub it and see exactly how the boats meet. Free, no account needed.

Rules cited

See the underlying rule: Rule 13While Tacking.

Related cases

  • Tacking too close (the lee-bow) · Upwind / Beating

    Red, on port, tacks onto starboard close ahead and to leeward of Green, who is on starboard. As Red passes head to wind and settles, Green has to change course to avoid her.

  • The lee-bower who claimed starboard · Upwind / Beating

    Crossing on port, Red tacks onto starboard right on the lee bow of an oncoming starboard-tack boat, Green. Green has to luff hard to miss Red's transom as Red settles. Red protests Green — “You're windward now, you have to keep clear of me!”

  • Port meets starboard on the beat · Upwind / Beating

    Both boats are beating to windward and their courses cross. Green has the wind on its starboard side; Red has it on the port side.

  • Two Optis tack at once · Upwind / Beating

    On a big shift, two boats near each other both tack onto the new tack at the same moment. As they come out of their tacks close together, who had to keep clear?

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