At risk of prolonging trivia... Of course wearing chinos is unusual on the beach. I can remember wearing trousers on the beach twice: once for wedding and once because we decide to walk on the beach after a meal at a beach side restaurant. Maybe this group is supposed to have spontaneously just decided to head to the beach after a meeting or service? If so, that's quite healthy for JWs. Few would plan to wear chinos on the beach, but at least the WTS is showing JWs having normal(-ish) fun, not the usual meeting, service, study, pray routine.
I didn't say wearing meeting clothes to the beach was normal (!!), just that covering up the skin (with some kind of clothing), especially in family settings, is hardly freakish behaviour of itself. I think I wrote that after a week on a family oriented beach (ie: a bay with no waves, everyone had small kids and most had beach tents: not the Gold Coast) when temps were in the 40s. Some people covered up more than others. No one wore chinos. But if some grandpa had chosen to, well, freaking good on him is all I'd want to say.