Alarm call?

[FUDGEY]

I was up putting a perch up at my kingfisher hide at first light today and I spooked a bird I couldn't see. It sounded similar to an Oystercatchers alarm call, but not near so high pitched and severe. The habitat is a thick reed bed which are 9ft tall and it was heard in a cut off channel from the stream which is approx 10ft wide and 4inches deep. I couldn't see it in the channel because of the dens reeds. I didn't hear it fly away either and I'm presuming it went into the reeds for cover. The only bird I have as a possibility is a water rail. I am pretty clued up on most calls and I've never heard this one before. I've also never knowingly heard a water rail so can anyone help me and let me know if one sounds similar to what I heard. I am on a phone so can't listen to calls on the net, thanks.

[Tursiops2]

Possibly a Little Grebe? The habitat sounds good, and they make a sort of "whinnying" call from cover. Water Rail is more like a pig squealing.
T2

[FUDGEY]

That's exactly what it would be. I've seen one the last 3 times I was up and got some nice close ups from my hide. I thought it was rather unusual to see them in fast running streams, saying that there are a few pools also. Thanks for ID that's the first time I've ever heard one.