DockWise — Anchor Line Calculator

Where are you anchoring?

Tap the map at your intended anchor spot, or search for a place. Nautical chart view shows NOAA charted depths in metres.

Drag the pin to your exact anchor position for best accuracy.

NOAA ENC: not for navigation, depths in meters

Mark swing-room hazards

Pick a hazard type, then tap the map to mark it. The shaded ring on the map is your swing circle. Anything marked inside it is a clearance problem.

Anchor pinSwing circleOther boatDockShallow area

Markers are for this session only. They aren't saved.

Tap the map to drop your anchor pin.

Drop your anchor pin to find out how much anchor line you need.

We combine live wind, wave height, charted depth, and current tide/lake level to tell you exactly how much line to let out, and when conditions are too rough to anchor at all.

DockWise provides educational guidance only. Bottom type, holding, swing room, and other boats' anchor lines are your call. The vessel operator remains fully responsible.