Here’s my experience at Pismo...
1) read the tide tables. The best time to take your rig on the sand is when the high tide is no more than 4’. That is, all of the “firm” beach roads are below the 5.5’ level. So as long as you can park/camp at 5’ or less...you are golden
2) before you head down to the sand: always, always, always...reduce your RV tire pressure to 20 pounds. There’s a Chevron gas station along Grand Ave with great RV access where you can refill your tires for free upon your departure (if you don’t have your own on-board air)
BTW...the local towing company will charge you $450 to pull an RV out of the soft sand
'17 Vegas 24.1