Same weird feeling. Anchored in Lake Champlain many years ago(and an earlier boat), I thought I dreamed I heard voices nearby and heard a funny 'clunk'. Soon after, we woke up on the beach! Not much of a problem, quiet night. I could see the rode through the clear water the next morning, hooked it, and pulled in the cut nylon, chain and anchor. It's never happened again, but in some busy anchorages, a nylon rode is vulnerable. I occaisionaly use a sentinel to keep the rode down in these rare instances. Usually though, the 50' of chain we carry is enough to prevent even a really close prop from cutting the rode. Still, an all chain rode will prevent this(but I prefer the lighter nylon chain rode).