Provided are containment structures having a substrate structure having a plurality of walls extending from a surface to define a space, wherein at least one of the walls has an overall negative slope; a first layer deposited in the space having a first surface energy no greater than 30 mNm; and a second layer deposited on top of the first layer. The vest has a V-shaped front neoprene panel, and a generally identical back neoprene panel. The indicator includes a chamber, which is isolated from the fluid circulation at least partly by means of the first sacrificial member.