addHook("MobjThinker", function(mobj)
        local player = mobj.player
        local swimming = 0

                if swimming == 0 and (player.cmd.buttons & BT_CUSTOM1)
                	   swimming = 1
                        end
			if swimming == 1 and (player.cmd.buttons & BT_CUSTOM2)
				   swimming = 0
 				   end
                if not player.powers[pw_underwater]
                        and not player.powers[pw_super]
                        swimming = 0
                        end
		if (player.powers[pw_underwater] | player.powers[pw_super]) and swimming == 1
			and not (player.pflags & PF_NIGHTSMODE)
			and not (player.pflags & PF_ROPEHANG)
			and not (player.pflags & PF_MACESPIN)
			and not (player.pflags & PF_STASIS)
			and not (player.mo.tracer and player.mo.tracer.type == MT_TUBEWAYPOINT)
				if (player.cmd.buttons & BT_JUMP)
					//move up if jump is pressed
					P_SetObjectMomZ(player.mo, FRACUNIT*8, false)
				end
				if (player.cmd.buttons & BT_USE)
					// move down if spin is pressed
					P_SetObjectMomZ(player.mo, FRACUNIT*-8, false)
				end
				if not (player.cmd.buttons & (BT_JUMP|BT_USE))
					// kill z momentum when not moving up or down
					player.mo.momz = 0
				end
		end
end, MT_PLAYER)