Chartplotter route zoom checks

A route drawn at an overview scale needs a closer review before it is used for automatic steering. Examine each leg, turn and route entry at chart scales appropriate to the data available. Zooming in does not create more accurate chart information, and a saved line is not evidence that a passage remains suitable.

Review the entry to the route as well as the route itself. Where is the boat now, which leg is active and what turn will the pilot command when it starts following? Inspect each transition at an appropriate scale and compare the screen with the water ahead. Brief the next watch on the expected prompt and who may accept it. After steering around traffic, repeat the check before re-engaging. The saved route has not changed, but the boat’s position has, and that can change the suitability of the next automatic correction.

Check the source and currency of the chart data and review the route against relevant current information. Inspect the whole leg, not only the waypoint symbols. A waypoint can be in clear water while the connecting line crosses a hazard.

Review transitions with the boat’s expected movement in mind. Ask how the installed system approaches, prompts for and executes a waypoint change. Do not assume every pilot offers the same confirmation option or that an electronic turn clears the surrounding water.

Before engagement, identify the active leg and the vessel’s position relative to it. Consider the correction the pilot may request from that starting point. Brief who can accept a transition and when manual steering is the appropriate choice.

After avoiding traffic or leaving the route, perform the entry check again. Record route amendments clearly so the next watch uses the intended version. Continue assessing conditions and traffic while following the route; the review is not a one-off approval for the whole passage.