surfing through Spain and Portugal

My boyfriend and I are planning a surfing trip in Portugal and Spain. Neither of us drive, so we are trying to find the easiest, cheapest option to get from San Sebastian, to Coruna, to Porto. We are taking 3 surfboards with us, including a 7"2 board( i think that's the length of it) as i have never surfed before. The train doesn't seem like such a good idea, cos our board bag is huge, it fits all three....Any suggestions??