I've liked Organic Maps for anchoring while sailing. Drop anchor, set a marker in OM, and have it as a backup source if I can't see the shore anymore during a storm (I've got other instruments).

Just been checking out OSMAnd+ from FDroid for one reason: depth contours for the Great Lakes. Seems reasonable from a quick check of some of my anchorages. Again, I have a back-up source for these as well: https://activecaptain.garmin.com/en-US/Map as well as paper & chartplotter. I'd love to see this depth layer in Organic Maps.

Organic Maps is lightweight and has a simple interface, sufficient for point to point navigation and browsing a map.

Osmand is incredibly powerful, customisable, and has many advanced features.