daytime
Look up Italian perfumers, Profumum Roma, they only produce the real stuff so no eau de toilette versions here, but for me their Acqua di Sale and their Vuolo AZ 486 give me a real beach bum feel sitting with a glass of ouzo after a morning tanning and swimming with some small mezze on my favourite terrace facing the sea in the Greek Peloponnese. Vuolo AZ 486 is also great I would think for those who holiday in the Pacific, Latin American region, it has coconut and tropical fruits but not overdone.For a similar effect you can also try Maitre Gantier et Parfumeur Bahania.
If you want more coconut and suntan oil, Comptoir Pacifique do a candied Vanille Coco, which if too much add some ozonic perfume to tone down.For a softer sillage and definitely better behaved than the beach bum look, go for Guerlain's new Acqua Allegoria, Lys Soleia. It has the signature of new Guerlain perfumer Thierrry Wasser who has done much to rebuild Guerlain's perfumes to their former creativity.
Lastly if you want the salty with a slight metallic twing, there is nothing better than to go for that 80's monument, Dune by Christian Dior You hesitate between car exhaust and metallic car paint and a salty seabreeze, but for those whose skins take to it it is a sex bomb!
nighttime
For me the nightime is about cooling down but enjoying the day's warmth of the sun. A shower and some sparkels and colourful wear, and I can feel the relaxation setting in. What to wear as a perfume? think back to that 60's french cult movie La Piscine (the swimmingpool) with Romy Schneider and Alain Delon, for me this means two perfumes which play in the general notes I mentioned in the beginning; Angel by Thierry Mugler (there is an eau de toilette version!) and Lolita Lempicka. You might think these two too heavy but rub some oil (Nuxe huile prodigieux if you can get it) and then a few spritzes of perfume, I swear heaven is there!