Born to Be Wild usually offers dolphin tours starting in Estepona, but maybe they have something a bit further towards Elviria. Call and ask.
If you want to see dolphins, we recommend you head towards Gibraltar for the Dolphin Safari, where you are guaranteed to see dolphins. It's definitely worth the drive. Make a day out of it visiting The Rock as well.
You can also try Fishing Trips, but ask for just a tour instead of the fishing. They are based in Fuengirola Port, which is about a 15 minute drive from Elviria.