Flatland skimboarding is skimboarding on long, shallow strips of sand, like a sandbar. Flatland has been progressing into a more technical sport, now that people are building rails and even quarterpipes.
This is a typical flatland board. It has a similar front and back so it is easier to spin. Also most flatland boards are made out of wood, because it's cheaper and you don't need to het out into deep water.
Flatland skimboarding is now also done away from any beach or sandbar. There has been a couple of competitions in Canada where a skim "pool" is built in the street. This is called Urban Skimboarding. Here are some pictures taken from Skimboarding.ca