Been following this kind of report out of Suffolk waterways for years and the number of people who dismiss it as "just a big otter" genuinely does my head in. Otters don't leave the sort of displacement wake people describe and they certainly don't linger in the shallows the way these things apparently do.
What time was this and how long did you observe it? That matters a lot more than most people realise. A three second glimpse is one thing but if you watched it for any length of time you start ruling things out properly.
I'd also ask about the smell. Sounds daft but several witnesses in this region mention a sort of muddy, almost musky odour that sticks around after the sighting. Nobody talks about that enough and it keeps cropping up independently which I find hard to ignore.
Don't let anyone talk you out of what you saw. Get back down there with a decent torch and a camera if you can stomach it.
