If you edit in potlatch2 and you have a good bing Bing image of the lake (that's the Ariel aerial image you can select in the editor) and you have some traces to check the alignment then you can draw around the lake as before just make sure the last node joins the first this will reveal lake as among the water features for you to choose. see http://wiki.openstreetmap.org/wiki/Lakes I understand there is a need to trace lakes and islands in opposite directions to set water to left or right of line hopefully some body will add that information for us.

If you edit in potlatch2 and you have a good bing image of the lake (that's the Ariel image you can select in the editor) and you have some traces to check the alignment then you can draw around the lake as before just make sure the last node joins the first this will reveal lake as among the water features for you to choose. see http://wiki.openstreetmap.org/wiki/Lakes I understand there is a need to trace lakes and islands in opposite directions to set water to left or right of line hopefully some body will add that information for us.