Just to clarify something for the OP. Rarely does LA get rain during "May Gray" or "June Gloom". Heck, it's practically unheard of to get rain in June.

MG/JG is just a marine layer, and normally only goes in about 1/2 mile in from the beach. This would be true if you were at the Manhattan Beach or Marina del Rey Marriott. There are times when the 'gray/gloom' extends more into the city & just 'hangs'.

It's actually a bit funny because I've been on a plane landing & have heard people say, wow - look at the smog & I want to say it's fog, you nimrod. And having lived in MB for 17 years, it was also pretty funny to have my windows open & on a really gray/gloomy day have fog roll through my living room.

Anyway, most of the time if there is 'gray/gloom', it's quite normal to have the beach socked in & yet drive a mile east & the sun is shining/not a cloud in the sky!! And even if it's gray/gloomy, it doesn't always last that long - could be a early morning thing, but could also last longer. Varies. Just like sometimes it will be gray in May, but not gloom in June & vice versa.

I'll let VickiSoCal handle the OC & SD questions, but I can certainly address any re: the Manhattan Beach Marriott or the Marina Marriott, along w/ getting to the beach/pool (MB's pool overlooks a golf course), places to eat, shop, directions, etc.

Cheers.