Mapping bays within lakes

I’m new to OSM. One thing I want to do is map a lake that I’m familiar with. I started mapping a bay within the lake, but I don’t think I did it correctly. I drew an area over the lake that roughly corresponds to the bay, but obviously I was not able to insert enough points to make it line up with the existing shoreline. There must be an easier way to do this. Ideally, I’d like to draw a straight line across the mouth of the bay and have it grab everything inside. Is this possible?

Looks like most people have just added a point (node) with a name to show bays.


So rather than trying to exactly duplicate the shore line, maybe just adding a point someplace in the bay tagged with natural=bay and name=‘whatever bay’ would be sufficient.

It might also be possible to split the way that forms the lake and then use relations, one for the lake and another one for the bay, that both use the way that goes around the bay.

Yes, most bays are just mapped as nodes. Which is usually good enough, because the bay probably doesn’t have exact boundaries anyway.

If you do want to map the bay as an area, then you can use the “Follow” feature in Potlatch 2 or JOSM.
ie something like this:

  1. Start drawing the bay
  2. Click on one of the nodes on the lake area
  3. Click on the next node on the lake area
  4. Press F (or Tools menu → Follow line in JOSM), then the way will automatically join to the next node
  5. Keep pressing F to continue all of the around the edge of the bay
  6. Then just click to draw the mouth of the bay, and make a complete area.