Advanced Scenario Check: Visual Aids

A yacht is approaching a fictional harbour at night as rain reduces visibility. The plan expects an east cardinal mark followed by a white sector. An intermittent group of three white flashes appears near the predicted bearing, but repeated timing has not established either charted Q(3) 10s or VQ(3) 5s. The white sector is not visible, depth is two metres shallower than the stage model, and the chartplotter and tablet repeat the same GNSS position and chart data.

Do not convert partial agreement into a route instruction. A group of three white flashes is consistent with an east cardinal character, but the incomplete period, missing sector, unexpected depth and common-source displays leave the aid and vessel position unresolved. The mark may be obscured, off station or misidentified; the yacht may also be somewhere other than the electronic picture suggests.

Preserve the briefed open-water option before troubleshooting consumes it. Keep one person conning, one on helm and one maintaining the outside lookout. Review safe speed and engines as the vessel and conditions require, use properly adjusted radar if fitted and operational, and record the light's bearing, complete timing attempts, depth trend and every source dependency.

Reopen the approach only when a repeated light character, current chart and warning status, depth, radar or physical geometry and independent position evidence form a coherent picture with a controllable escape. If that standard is not met at the last safe point, hold, divert or abandon the approach. Port permission or a desired track cannot replace the missing navigation evidence.