Hi, discovered I had no coolant left in the scooter so had to fill up with water.

Maintenance and technical stuff is new to me so I haven't a clue about this.

What coolant does this take and where can I get it in the UK?

Manual just says take it to a Yamaha dealer. Internet won't tell me anything at all!

Thanks in advance.

Any coolant suitable for aluminium engines will do if your really stuck. Use as per the bottle. 

You need to figure out where the coolant has gone too.