Hey, thanks for the advice folks!

The race is this Sunday.

I do not run too often on a real beach, but we have a lot of inland dunes here in my place, this means loose, dry sand while I expect to find heavy wet sand (quiet compact, actually). I was trying several types of shoes but I wasn't quite sure if I was doing the right thing.

I am not yet going to use "barefoot" shoes since I have been training in normal trainers and flats, I am very tempted to try to do part of my mileage in "Bikilas" as they have just freshly paved a large amount of miles of bike paths with new asphalt (it looks soo inviting...), I will however leave it for after this race.

I have finally chosen a pair of K-Swiss Natural II, light and with an excellent ability for fast drying (tested in rain and snow). The drawback is that the profiles of the soles is very shallow which will be a handicap on the dunes at the end of the beach (loose sand). Finally a pair of gaiters will make a huge difference (I hope).

Thanks again for the advice people!