Thing type 109, Skim, is a water enemy used in Deep Sea Zone. As its name implies, it skims on top of water surfaces and drops bombs when the player is under it. It does not have to be placed on top of the water manually, the game will automatically detect any water FOF and place it on top. If there is no water FOF where it is placed, it will attach to the floor and not move, but this usage is discouraged as it looks awkward.
This enemy should not be overplaced in smaller bodies of water, especially when the player is forced to stay in one spot for a long period of time or stop for air. Once these enemies are above the player, getting away unharmed is very difficult. Thus, Skims are best used for sections that allow the player to move moderately fast.
