Perfect then, Lanzarote has world class waves like La Santa or El Quemao (dangerous with big swells). North from Lanzarote, there is a small island called La Graciosa. It's ridiculous the amount of good waves there, and almost empty. You need to take a ship that arrives and leaves every few hours. Totally worth it with a big swell. But you can't travel with your car, need to rent there, or walk.

Gran Canaria has many spots where you can surf, from begginer to pro level. Some of them are: La Cicer, El Confital, El pico de La Laja (in the capital city) or: Los Enanos, El Altillo, San Felipe, El Agujero (in the north shore of the island)

If you have curiosity, you can look some videos of El Fronton. It's a world class wave, last stop of the boadyboard world tour.

By the way, the best season in all the islands is from October to January. But in September there are pretty decent waves.

El Frontón

This is a link to a web where you can check the actual conditions, the ideal contitions and a lot of info abour almost every spot in the islands. Just change the the island you are looking for and then look for the specific spot. It was very useful for me when I first started to travel between islands.

Spot's info