Sturgeon on the fishfinder

Found this on Coastside,  always wondered what they looked like on the fish finder!

It looks like a sturgeon!

Looks like someone in a blue shirt!

Looks like Blue but we can all tell it's not by the Fishfinder.

Ethan got the crap scared out of him one day at bean hollow when he saw the shape of a GW on his FF about 15 feet down.  I guess it could've been a school of chovies and a coincidence, but he insists the FF showed cross-sections of shark as it passed under him. 

I had the same experience at Davenport 2 years ago. I was drifting for Halibut in 60 ft. of water....and the my FF turned solid black for a few seconds. I just thought that it was sea lion that swam under the yak....but I never saw it surface (never even saw one the entire day)....so I thought of the worse and quickly pulled my stringer of rockfish on board. Since then, I've never hung any fish on the side of the yak 

Could you see a shark on your fish finder? A fish finder bounces it's signal off of things that are a different density than water Fish bodies are the same density as water, so the signal bounces off the air in the fish. Shark and sturgeon don't have air bladders like say rock fish.

I've heard people say they can see strurgeon and I guess that's true. What I don't know is what makes the sturgeon show up on your screen. I can only guess that they somehow have air in their body. Sharks and sturgeon are similar fish, so the same goes for sharks. I wonder if it has anything to do with what they are feeding on and how much they have eaten?

The only time I have seen a shark on a fish finder was in Bodega Bay. We were salmon fishing and tracking bait. We saw this screen image that was like a perfict shark. We knew this was the school of bait, but it had formed up into a nice sharky shape!