A very accessible site
Both by plane and car is very easy to reach Catoira. It is not very common, but it can also be reached by boat. If you want to go by car from a distance, the most common is to use the AP-9 in the direction of Pontevedra. Once nearby, it is well signposted. If you have any questions, you can follow the signs to Villagarcía de Arousa, which is quite close by.
To come by plane, you have the Airport of Santiago de Compostela (SCQ) at 52 Km or the Airport of Vigo (VGO) at 63 Km. There is also the possibility of flying from the Airport of A Coruña (LCG) at 1 hour by car. From the Airport of Oporto-Francisco Sá Carneiro (OPO) is 2 hours by car (perhaps the latter is a little further away, but with more international connections).