We maintained the following balances with our unconsolidated affiliates as of March 31, 2019 and December 31, 2018:

(In thousands)	March 31, 2019		December 31, 2018
Due from related parties:
Sonatide (Angola)	$	92,202		109,176
DTDW (Nigeria)		26,847		23,775

Due to related parties:
Sonatide (Angola)	$	29,611		29,347
DTDW (Nigeria)		10,634		5,625

Due from related parties, net of due to related parties	$	78,804		97,979

Amounts due from Sonatide represent cash received by Sonatide from customers and due to us, amounts due from customers that are expected to be remitted to us by Sonatide and costs incurred by us on behalf of Sonatide.

	Three Months
	Ended
(In thousands)	March 31, 2019
Due from Sonatide at beginning of quarter	$	109,176
Revenue earned by the company through Sonatide		15,387
Less amounts received from Sonatide		(25,285	)
Less amounts used to offset Due to Sonatide obligations (A)		(6,021	)
Other		(1,055	)
Total due from Sonatide at end of quarter	$	92,202

(A)

We reduced the respective due from affiliates and due to affiliates balances each period through netting transactions based on agreement with the joint venture.

The obligation to us from Sonatide is denominated in U.S. dollars; however, the underlying third-party customer payments to Sonatide were satisfied, in part, in Angolan kwanzas. We and Sonangol, our partner in Sonatide, have had discussions regarding how the net losses from the devaluation of certain Angolan kwanza denominated accounts should be shared

After offsetting the amounts due to Sonatide, the net amount due from Sonatide was approximately $63 million. Sonatide had approximately $50 million of cash on hand (approximately $20 million denominated in Angolan kwanzas) at March 31, 2019 plus approximately $14 million of net trade accounts receivable to satisfy the net due from Sonatide. Given prior discussions with our partner regarding how the net losses from the devaluation of certain Angolan kwanza denominated accounts should be shared, we continue to evaluate our net due from Sonatide balance for potential impairment based on available liquidity held by Sonatide.

Amounts due to Sonatide represent commissions payable and other costs paid by Sonatide on behalf of us.

	Three Months
	Ended
(In thousands)	March 31, 2019
Due to Sonatide at beginning of quarter	$	29,347
Plus commissions payable to Sonatide		1,475
Plus amounts paid by Sonatide on behalf of the company		5,364
Less amounts used to offset Due from Sonatide obligations (A)		(6,037	)
Other		(538	)
Total due to Sonatide at end of quarter	$	29,611

(A)

We reduced the respective due from affiliates and due to affiliates balances each period through netting transactions based on agreement with the joint venture.

Sonatide’s principal earnings are from the commissions paid by us to the joint venture for company vessels chartered in Angola. In addition, Sonatide owns three vessels (one of which is currently stacked) that may generate operating income and cash flow.

For the three months ended March 31, 2019, our Angolan operations generated vessel revenues of approximately $15 million, or 13%, of our consolidated vessel revenue, from an average of approximately 35 company-owned vessels that are marketed through the Sonatide joint venture (14 of which were stacked on average during the three months ended March 31, 2019). For the three months ended March 31, 2018, our Angolan operations generated vessel revenues of approximately $14 million, or 16%, of our consolidated vessel revenue, from an average of approximately 40 company-owned vessels that are marketed through the Sonatide joint venture (18 of which were stacked on average during the three months ended March 31, 2018).