4. Vessels, net:

The amounts in the accompanying consolidated condensed balance sheets are analyzed as follows:

	Vessel Cost		Accumulated Depreciation			Net Book Value


Balance December 31, 2017	$	1,167,500	$	(190,202)	$	977,298
Other additions to vessels’ cost		409		—		409
Depreciation		—		(30,330)		(30,330)
Balance December 31, 2018	$	1,167,909	$	(220,532)	$	947,377
Depreciation		—		(30,680)		(30,680)
Balance December 31, 2019	$	1,167,909	$	(251,212)	$	916,697

As of December 31, 2019, all vessels comprising the Partnership’s fleet were first priority mortgaged as collateral to secure the $675 Million Credit Facility, further discussed in Note 5.