#1 a (huge) hat
The bigger the better! This one I bought in Corsica a couple of years ago and I just can't get enough. It instantly umphs up your outfit, even if all you have on is a bikini.
#2 a swimming suit
This summer I went for a white sporty top and sunset coloured bottoms, the first one reminiscent of AW swimsuit (A for Alexander and W for Wang, bien sur) but for a fraction of price. Both look amazing when you've got a bit of tan!
#3 a shoe
Or two. Converse to have long walks, or (or should I say and?) plastic sandals, chunky or chic, or both, as you prefer.
#4 a sunscreen
Letters to check on the packaging: uva, uvb, spf 50+, ppd 42, ultra-light. I'll take two.
#5 a good read
Nathalie Sarraute speaks about her childhood, spent between Russia and France, in a form of a dialog between herself and her second self, between the right side of the brain and the left one, one more rational and one a bit more feeling-based, but both equally objective. It is not only an autobiography, but a book about language and writing as a vocation. Loved it.