What do I need for DS for vacay?

Ardmhs83

We are leaving to go to Myrtle Beach (8 hours away from good ol' WV) in 2 weeks.  This will be our first beach trip w/ Carter.  What things do I need for him to make the beach experience as best and as easy as possible?  Of course we have him two swim trunks/tops, sun screen, hat and a pool floatie, but what else am I missing? 

We are also trying to figure out the best time to leave as well.  Everybody keeps telling us to drive at night, but we don't want to be totally exhausted the next day at the beach.  We would be miserable.  So we are thinking that we will leave in the afternoon around 4-5ish.  He always gets fussy and tired around 7ish in the evening.  So we are thinking we will drive until 9-10pm, stop and get a hotel and all of us get some rest.  Then we can wake up the next morning and drive the other 2-3 hours.  Anybody else do something like this?  And how did it go?