I have never been very good at beach game as well. But from observing others and some experience, I think it's all about spontaneity and being a cool social guy. Asking for beach volley ball when you're with a group of friends is a good idea. If you have a ball which may go in the water, you can play games there with girls. It's realy awesome when you just met a girl and she comes very close to you in the water and wrestles with you trying to take the ball off you

.
If there is a cocktail bar on the beach, then you have a nice venue where you can come in contact with girls as well.
If you are going often to the same place at the same beach (at the same hotel) you might see people more often and start to recognise them. Getting in touch with them is good as well, it shows that you're social and that's also a bonus. Plus, those people you meet may know hot girls themselfs.
Further, working on your body is good. At the beach you don't have a tshirt on to hide your beer belly, and looks are often more important, but not sure how important though.
And, in the end, like always, be brave and dare to open girls. I have regret not opening girls often at the beach and seeing friends and others doing it for me, and having positive reactions and succes, because many are there to have a good time. And although they might look intimidating in bikini, they too are having a summer time, and they too are experiencing "summer vibes" (wheter that means they're just more feisty than normal or that their pussies are screaming for a fuck). You might be suprised how open they are.
PS: your friend don't seem to me like an AFC at all, if he is able to pull hb9s