Krystal,
My apologies - I think brain-fade has set in, the stretch of water concerned may be Windermere, as I think Ambleside was mentioned.
The writer was very cagey about the exact position for obvious reasons, I'll try to find his post on Pprune a few months ago.
Discovery of a Wellington too was mentioned, which is probably where I got Loch Ness from; may be another in Windermere !
A side-scan image did seem to show a large aircraft, with as I recall one engine looking as if was drooping badly.
Like Loch Ness, I should think Windermere was quite appealing ( especially for a flying boat ) for a forced landing compared to the surrounding terain...
There was also mention of a Sunderland factory on the shore opposite Ambleside ?
So it may have sunk through something happening ( or neglect ) while in boat mode...