English: Caoutchouc watch strap (Extreme) for diving watches. With increasing depth and rising water pressure the (sleeved) wrist of a diver is exposed to compression effects that have a shrinking effect on the wrist circumference. Many watchstraps intended for diving watches have rippled or vented sections near the attachment points on the watch case to facilitate the required flexibility to strap the watch exaggerated tight for normal wear at the surface whilst keeping the watch adequately tight in place on the divers' wrist at depth.