Quicksand Fans

is set in a marsh that looks like morcombe bay starring harry potter http://www.youtube.com/watch?v=cshZLRteogA http://www.youtube.com/watch?v=arixaTWmIA0

http://en.wikipedia.org/wiki/The_Woman_in_Black

Looks promising... and spooky.

I saw the 1989 TV movie years ago... no sinking in it, although it is mentioned... and it was genuinely frightening. A really creepy ghost story. This one looks like it has the potential to scare the crap out of you...

in the second youtube link, somebody, or something coming out of the muck at the 1:00 mark and 1:05 something oozeing from the bed not sure, could be fun