Tall stalks with brown bulge near top, growing from grass-like foliage
No interactions present.
The spikes look long and thin which reminds me more of Lesser Bulrush (Typha angustifolia). I've no idea whether you get this species on the IOM.
If there are remains of male flowers present above the female spikes (the obvious'bulge'), it would confirm one way or the other (there is an obvious gap between the male and female spikes on Lesser Bulrush). I can't be sure when I try to zoom in.
I will try and get back to the site and have another look and photograph. It is on the edge of a pond and difficult to approach, and I have shakes that make close-ups or long range photo's difficult.
I was not even aware that there was a different species (my main interest is marine) though I becoming more interested in "topside" stuff.
So many thanks and I will try and follow it up.
Geoffrey the diver
Tim Rich and Duxbury Rambler have both agreed with your initial ID as T. latifolia, and both are very experienced, so I'm sure it will turn out to be this species after all rather than Lesser Bulrush!
That will save me an accidental paddle.
Lat/Lng: 54.1745, -4.4953
OS grid ref: SC372782
close to fresh water reservoir