5. Vessels, Net


			Accumulated
	Cost		depreciation		Net book Value
Balance, April 1, 2015	$	439,180,669	$	(19,204,616)	$	419,976,053
Additions		1,211,595,756		—		1,211,595,756
Disposals		(268,281)		26,060		(242,221)
Depreciation		—		(26,341,945)		(26,341,945)
Balance, December 31, 2015	$	1,650,508,144	$	(45,520,501)	$	1,604,987,643

The additions to Vessels, net represent amounts transferred from Vessels under Construction relating to the cost of our fifteen newbuildings that were delivered to us during the nine months ended December 31, 2015.

Vessels, with a total carrying value of $1,601.3 million and $416.0 million as of December 31, 2015 and March 31, 2015, respectively, are first‑priority mortgaged as collateral for our long-term debt facilities (refer to Note 7 below). No impairment loss was recorded for the periods presented.