Ebb Tide, Two-Metre Swell, and a Deadline
You are returning to harbour in an 8 m launch after a day fishing. The harbour entrance has a shallow bar with 1.5 m charted depth. It is the last hour of a strong ebb tide, running about 2 knots out. A 2 m swell is rolling in from the west with an 8-second period, and the wind is 15 knots offshore. From outside, you see occasional white water breaking across the bar, and the sea steepens where the ebb meets the swell. You have a seasick passenger and a tired child aboard, but no emergency. The next flood tide is in about three hours. The alternative harbour is 12 nautical miles south and has a deeper entrance. You have VHF, charts, lifejackets and a working engine. What do you do?
1. Assess the bar conditions. What is your decision?
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The bar is unsafe. A 2 m swell with an 8-second period is already steep, and a 2 kt ebb running out against it will stand the waves up and produce breaking sets, exactly what the white water shows. The charted 1.5 m depth leaves little margin for an 8 m launch in a trough. The fact that the passenger is seasick and the child is tired creates pressure, but no emergency justifies crossing a breaking bar. My decision is to hold off, keep well seaward of the breaking zone, and wait for slack or the flood. The deeper alternative harbour 12 nm south is a better option if conditions are manageable and the crew can make it.
2. If you wait outside, how should you manage the boat and crew?
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Wait in safe depth, clear of the bar and the breaking sets, with enough sea room to keep the bow into the swell. Keep lifejackets on, secure loose gear, monitor Ch 16 and the local weather, and give the seasick passenger fresh air and a place to sit low and central. Log the wait and tell someone ashore or Coastguard of your intention. Do not anchor in the bar entrance or drift onto the shoal. Reassess visually and with local information before committing; the ebb will ease and the flood will flatten the sea, but the change may take hours.
3. If you are already committed and a set breaks ahead, what handling actions do you take?
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If committed and a set breaks ahead, do not turn broadside or try to turn back in the surf. Keep the bow up, reduce speed enough to stay on the back of the swell but keep steerage, and avoid taking a breaking crest on the beam. Secure everyone, keep lifejackets on, and have the radio ready. Once through, keep clear of the entrance and check the boat for water. If the engine fails in the surf, anchor if possible, call Mayday, and prepare to abandon. The aim is to avoid being pooped or rolled, not to maintain planing speed.