A bunch of re-enactors trying to retrace George's crossing of the Delaware underestimated the strength of the current and ended up having to be pulled to safety by a rescue boat. But these weren't the failings of inexperienced men. They'd been doing this since 1976 and had never failed to cross in the past. However, this time, the current was too much for them. I'd refer you to the AP story but that page has some problems with it.