Sam, they are made for sea angling by a company called Ron Thompson,
i have found them for £7.95 at www.gerrysfishing.com
&
http://www.sportfish.co.uk/acatalog/Gloves05.html - £8.95
The ones below are also great for longer Sumps and really really really wet caves that are very very very cold!!!!!
http://www.nwac.co.uk/acatalog/Ron_Thompson_Clothing.html - £7.50
(Bottom of page)
Personally i really rate neoprene gloves, cotton ones are good for dry caves, but when you are in constant water and everything you touch is wet and cold they are certainly the way forward.
Stu