I went to Lahaina last August for a week. The surf was relatively flat-knee to thigh at best. I didn't have much luck finding a shop that had legit boards to rent. Maui tends to be the more touristy island, so they expect everyone to ride foam / BIC boards. I wish I could have brought my own, but I didn't want to risk damage and pay the extra money to haul them around the airports. As for surf spots, the one I surfed almost everyday was just south of Lahaina. I can't remeber the name, but there is a main road that runs along the coast with small parks/beaches spotted along the road where mostly everyone surfs. I also heard that Maui is very local, so if you manage to find a less popular spot be careful. If you get a chance, go to Oahu which is a lot more fun, relaxed, and less touristy in my opinion.
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Mexico / Central America