A tethering device for a boat may be mounted to a dock so that the top surface of the tethering device is flush with the top of the dock. Inside the housing is a retraction reel storing a sufficient length of line to provide tethering of the boat to the dock while retracting excess line back for out-of-sight storage but leaving the pre-selected length of line extending from the tethering device. The housing also has a line locking mechanism to hold the line at the pre-selected length so as to prevent the boat from drifting away taking line with it.