Purely for interest rather then reality as neither side wants any conflict and the spanish definitely couldn't afford it.
Both sides operate a similar number of ships RN-98 SN-95 but the RN has a significantly higher overall tonnage (350,000 vs 250,000 if memory serves) as most of the ships are bigger. We have much more in the way of advanced attack subs but a similar fleet structure. The RN are often considered top be one of the best trained and exercised forces in the world while the spanish reputation is not as great, although trusting reputations cant bite your in the backside.
The spanish operate a harrier carrier very similar in size and role as the ark royal until the government decided that the UK should be seen as the kitten of the seas
Hopefully if anything does kick off the spanish would have the decency to wait 10 years for our carriers and subs to be ready, presuming the government doesn't sell them off too.
But on the other side the Spanish would have home game advantage, it would be a very interesting strategy game match up but no one on any side wants any conflict. It would be a disaster for all involved if diplomatic relations were damaged over a couple of idiot fishermen. Also as a sidenote HMS Sabre being listed as the main ship in the article is barely much more then a fishing boat itself.
http://en.wikipedia.org/wiki/Scimitar_class_patrol_vessel