Reptiles from the Past--Alive

I was going into a restaurant. As I looked out the winddo , I saw a obgect in Hutsin river.
It looked like a back of a sea reptile. The creature that I saw may be a close relative of Sticsasaur. Sticsasaur is a marine reptile that had a long neck, up to half of its body length. Every few hours, it had to come up to the surface to breathe. Another creature that I can describe that is like a Sticsasaur is called "Nessie", or the Loch Ness monster.