I feel like throwing a party on the beach is very hit or miss. The goal of any party is to get the attendees to enjoy spending time together, but when people are on the beach, everyone is spread out. Unless you have centralized entertainment and a designated space that is visually obvious, beach parties can be quite a challenge.
Party goers have known this for a while which is why medium to large sized gatherings at the beach are generally avoided unless promise of social norms like a dj or a mud wrestling contest are mentioned.
I’m on my way to a beach party now. I expect it to be small enough for us to be able to enjoy time together despite the size of the setting.