Hi Janet, the water park near Kos town is out toward Psalidi, about two or three Kilometeres from Kos town itself. Don't know how busy it is as I've never been.
There is another water park near Mastihari, sort of between Mastihari and Marmari (not on the main road) which looks to be fairly new. Only drove past on the local bus so don't know any details i'm afraid.

Andy.

There are some reviews of the waterpark on http://www.JustKos.co.uk

Direct Link

http://64.141.115.239/kos/comments.asp?item_ref=365

Most reviews seem too say not too busy, but don't know as I have never been my self.

Hope this helps.

smee, could the new water park you saw belong to the new hotel that first choice are building, its somewhere near tingaki? karen

Hi Karen, there is a big new hotel opposite the waterpark. Not sure who owns or runs the hotel, but I suppose it is possible that the waterpark could be connected with it.
It is somewhere on that road from Tingaki, Marmari to Mastihari, but I thought it was nearer to Mastihari as the bus didn't turn of until you hit the new section of the main road which was laid last year- road goes off at sort of "Y" junction rather than crossroads.
It didn't look as if the waterpark was open for business when we passed it, but the hotel appeared to be open.

Andy.

like the others have said its towards the psaldi end. its not huge and and only has a few shoots etc. i think it was about 15 euro for an adult

A few details on the new waterpark near Mastahari. Not many details, but as it is this new I dont suppose there will be hat much info available.

http://www.kos.me.uk/index.php?topic=10219.0

thanks fot that info, still not sure if thats a seperate waterpark or the one belonging to the first choice hotel.still, it sounds promising, and when we go to kos, i am sure we will visit it anyway................xxk