Re Mark's post below.
I have never sailed my own small boat in "Green Spain", but have spent many weeks in the area for "business purposes", over a period of maybe 5 years. including two 6 week summers with the family in tow; rented wayfarer type thing a couple of times.
One small problem is the use of a multitude of languages here (Spanish/Galleago/Basque) can be confusing in place names; OK once you are aware. There also seems to be some sort of Asturias/n? dialect?
Galicia; What a fantastic place! can't recommend highly enough!
If you enjoy Falmouth, this is a bigger & better version - As has been said before - think of South coast Cornwall but with bigger Rias (Rias Baxias are the ones further South, onto the Atlantic proper) better weather, food and wine; beer not so good tho ;-).
Lovely friendly folk - even more so if you are one of their Celtic brethren (as a Cornishman it was noticeable - that currency is also valid with many of the Basques, I found out!).
Not as busy as we have had to become used to in the UK.
Roads excellent. Port facilities generally excellent compared to ours.
Rias Altas, the ones along the N coast opening out onto Biscay , are also beautiful and of interest, as is much of the N coast in Asturias, Gijon ( industrial), and over as far as San Sebastian, Pasajes (Pasaia) etc.
However, can be dodgy up there on N coast - with dangerous access for small boats in poor weather; think more N coast of Cornwall - StIves/Hayle, Newquay, Padstow style). Beware.
You will drive past all this en-route to Rias Baxias from Santander/Bilbao.
Take the chance to go to Santiago de Compostella - but park well away from the city; no chance in city if towing. I was paying more to park my car than to rent it x 2.
Anywhere close to Cabo Finisterre has been brutal when ever I've been any where near, even on a "calm" day; not for me in a Swallow!
Old Pontevedra is a hidden gem. Don't be put off by the stink of the paper works just down the river.
We have been back to the Pontev area on holiday since my period working there - it was that good.
there were cheap flights (EasyJ?) from Stanstead to Santiago.
We plan to take the boat once time allows - retirement?