15 pounds is a paperweight, only suitable for a rowboat.
OTOH, you may not have a problem, in 20 feet of water you should have
paid out 80 feet of chain (NOT rope) so 15 yards of movement does not
necessarily mean that the anchor has moved if there is a strong current.


even in a Midwest prarrie lake?

nah, *then* a a 15# anchor is what you want.