Close encounter of the Orca kind

[CAVU]

I recently had a close encounter with a marine mammal. I just returned from a fishing trip off the west coast of Vancouver Is. While trolling for salmon with downriggers a pod of Dahl's Porpoise starting playing near the bow wave. About 5 seconds later one speeds under the boat and hits the downrigger cable, which instantly shreds near the boom pulley. I had never had this happen before or heard of it. The fishing line came unclipped and we recovered the flasher and lure, but lost the 15# cannonball and release clip. We couldn't see what became of the critter but I would guess it was severly injured. Anyone ever have anything like this happen?