Brachiosaurus - just go with it
Bear with me for a moment.
There was a theory, back in the '30's, that Nessie was a brachiosaur who walked about the bottom of Loch Ness and that's how we saw her head.
Loch Ness is stupidly deep. So deep in fact, that it holds more water that all of the lakes in England and Wales combined, even although it's surface area is not that vast. But there's no way a creature can put it's feet on the loch floor and have it's head stick out the surface.
But I wanted to have a closer look at the neck structure anyway, since that Surgeon's photo is so popular. Plesiosaurs just couldn't get their necks into that position - but these guys could. Them and swans.
With the Surgeon's photo very likely a hoax, and few other Nessie sightings seeing the neck do that - I think it's fine if my Nessie can't make that movement. Maybe she moves her body in different ways so she can poke her head out - but after a bit of a brachiosaur study I'm happy that her neck doesn't look like this.