it's a calm day at sea, and kyle nash is salmon fishing with his brother jason and father kelly. >> there was hardly a breath of wind. >> while the air remained still, the water suddenly starts to move. >> what is that? go get my binocs, quick. >> my dad was saying, hey, kyle, what are those things there? i was like, i don't know, they look like waves. he's like, those aren't waves. >> yeah, looks like a gigantic eel. >> he goes, you better get your cameras because this is something that we need to crash on film. >> come here quick with your camera. >> kyle and jason both grab cameras and start recording. >> look how fast they're going. >> look at how big they are. >> you couldn't tell if it was sea snakes or something that -- might have been seals. >> see it? a sea snake. >> holy [ bleep ]. >> but then we realized that they were some sort of creature that we hadn't seen before. >> this [ bleep ] is huge. look how fast they can go. look at the wave it's making. >> this one's almost 40, 50-feet long. >> it quickly becomes clear they're not filming one animal but several. >> there's more th