Hugh,
I spent a couple of years at 25 Flight recently (and on Gazelles a while back) and as Flying Microphone says it sounds like Chaa Creek although I wouldn't be surprised if the place you mentioned either no longer exists or is going under a new name and has been completely rebuilt!!
As you probably know Belize has, over the last 15 years, changed from what was a sleepy Caribbean back water to a real up and coming tourist destination - consequently there are a lot of jungle lodges springing up in the Mountain Pine Ridge area, many of these with HLS's. The current training done by BATSUB tends to happen in that area as well and up towards Gallon Jug which means that the majority of landing sites (and camps, OPs etc!) that people remember from British Forces Belize days have been out of use for some considerable time and the jungle doesn't take long to claim back a small clearing - we had a team of LECs whose only job was to keep our landing sites clear (and a full time job it is!).
When you get out to Belize and if you have time, I'd suggest popping into Price Barracks (what used to be Airport Camp) and speaking to the guys up at the Flight - I'm sure they'd be happy to help you find the place you're looking for!
And for all the Puma mates, you might like to know that every year the CO is flown down to Salamanca Camp (which has been a logging camp for 10 years) and the memorial is cleared and a wreath laid.