Atreus was there! He brought Lore and Bessie with him, the latter of which got carried around a lot because he insisted on going but was a weenie. He gave Lance a knife with hilt that he carved from bone. (this doesn't have the knife part pictured just imagine it is curved and pointy) He was in swim trunks and handed Bessie off to someone so he could go swimming at some point, chilled out otherwise.
Gansey was there as Blue's +1, he gave Lance a card with cold hard cash (yw birthday boy) and made sure to eat pizza with pineapple on it because he likes living dangerously. He got into vollyball most definitely, he's sporty bro boy. also Alvaro loves the beach so I don't usually get to do this
And Iggy was there with his boyfriends. He is pretty much the epitome of this but he had at least one dog cuddling up to him pretty often without complaint. Expect the usual heart eyes, he could've gotten dragged into vollyball and he would like to state he did not sign off on Keith flying his baby.