You have plotted a waypoint-to-waypoint route on the GPS plotter. What critical check must be done before the passage?

A. Only the final waypoint needs checking — intermediate waypoints are standard safe-water positions

B. Verify that the straight lines between each waypoint clear all dangers — GPS routes plot on the surface of the Earth and do NOT automatically avoid hazards. Each leg must be checked against the chart for shoals, rocks, and traffic

C. GPS routes automatically route around all charted hazards

D. The paper chart is only needed as a backup — GPS route planning is self-verifying

A. The passage plan need only identify the destination — diversion decisions are made in real time

B. A port of refuge provides a safe haven if conditions deteriorate. Suitability factors: accessible in the expected conditions (depth, bar, height of tide); distance from passage track; available facilities (fuel, medical, communications); whether it can be entered at night; holding ground if anchoring is the only option

C. Any port on the chart is automatically suitable as a refuge regardless of conditions

D. Ports of refuge only matter for vessels without an engine — sailing yachts can always divert

A. A point on the passage (headland, strait, harbour bar) that can only be safely transited within a specific tidal window — the departure time and speed must be calculated backwards from the tidal gate time to ensure arrival within the window

B. Tidal gates only apply to vessels over 20 metres in length

C. A tidal gate is another term for a tidal stream atlas symbol on the chart

D. A lock gate at a tidal harbour — only relevant to inland waterways