How close to the coast am I?

This matters in Croatia: within 300 m of the coast the speed limit is 8 knots, and the innermost 50 m belt is for swimmers. Blue Dolphin draws exactly those bands on the chart, along every coastline.

50, 150 and 300 m shore bands with distance line — Close in, zoomed in, bands on: the three belts and the red distance line.

Press and hold the ruler button (bottom-left) and the shore bands light up: 50 m, 150 m and 300 m from the waterline, plus a red dashed line from your boat to the nearest point of shore with the live distance on it. Release, and they fade. Double-tap the ruler button instead to keep the bands on while you manoeuvre. A single tap lets them go.

That one glance answers the two questions that matter close in: am I inside the 300 m zone (then keep under 8 kn), and how much water do I have to the rocks? If you would rather not check at all, the app watches this for you (see Warnings).