Does anybody know where you can obtain these in the UK?I bought one many years ago but it was on it's last legs when I last saw it and currently locate it.

Doesn't Phil Brown sell them at Caving Supplies in Buxton?
Might be worth a glance at the website.

I thought of starting at shops but then wondered if people had stopped using them. Thanks John, I will take a look.

I get waterproof notesbook and regpaper books Surveying companies. I use York Survey Supply:
https://www.yorksurvey.co.uk/chartwell-books-c102x3183375
https://www.yorksurvey.co.uk/waterproof-notebooks-paper-c102x3783642
And there are also the Weatherwriter books which you can buy direct;
https://www.weatherwriter.co.uk/Category/waterbooks-waterproof-files/

They all work - it depends how big a book you like, whether you like to take the same notes underground again, and how important a hardback surface is.
For expedition use I like the paper in the waterproof books, but mounted in an aluminium clipboard.
For personal use a ragpaper field book can work well so long as the cave is not absolutely soaking.

What do you write with? I was out using the chart well  waterproof red book with a biro recently and struggled once wet. Pencil HB was not much better.

I got some of the waterproof pencils and pens from Weatherwriter when I ordered some books. The pencils have a lanyard, which must be the coolest pencil ever invented!

https://www.weatherwriter.co.uk/Item/seawriter-pencil/