“Safety precautions are a big part of underwater hockey. Before each game starts, one of the rescue divers uses a chainsaw to cut holes in the rink so the players can get in and can get out”. “Because divers can easily get disoriented during a game, in case one of them is too exhausted to reach the hole, or can’t find it, four divers equipped with oxygen tanks supervise every match”. Several large holes, 2 x 1 meters, are cut in the ice next to the rink so that players could easily rise to the surface for air. “Each hole marked with a big national flag to avoid confusion” (deeperblue). The holes are located perpendicular to the nets (on the long side of the rink where a bench would be located in any sport), where players in hockey would typically sub in and out. The holes are large enough to fit the divers and support divers who could quickly dive in and get to anybody who needs help. Some rinks even have holes in the ice located within the nets in case a diver is not able to swim over to the side of the rink.