Charter Hire Expenses
Charter hire expenses for the vessels chartered in from third parties were $13.6 million and $6.2 million for the nine months ended December 31, 2020 and 2019, respectively. The increase of $7.4 million, or 120.5%, was caused by an increase in time chartered-in days, which increased from 275 for the nine months ended December 31, 2019 to 560 for the nine months ended December 31, 2020.
Vessel Operating Expenses
Vessel operating expenses were $58.0 million during the nine months ended December 31, 2020, or $9,591 per vessel per calendar day, which is calculated by dividing vessel operating expenses by calendar days for the relevant time-period for the technically-managed vessels that were in our fleet. Vessel operating expenses per vessel per calendar day increased by $889 from $8,702 for the nine months ended December 31, 2019 to $9,591 for the nine months ended December 31, 2020. The increase in vessel operating expenses for the nine months ended December 31, 2020, when compared with the nine months ended December 31, 2019, was primarily the result of a $5.6 million, or $930 per vessel per calendar day, increase in operating expenses related to repairs and maintenance, spares and stores, and coolant costs, which is inclusive of an increase of $1.3 million, or $219 per vessel per calendar day, in operating expenses related to the drydocking of vessels.
General and Administrative Expenses
General and administrative expenses were $22.8 million for the nine months ended December 31, 2020, an increase of $5.1 million, or 28.8%, from $17.7 million for the nine months ended December 31, 2019. This was driven by increases of $2.0 million in annual cash bonuses to certain employees, $2.2 million in salaries, wages and benefits, and $1.1 million in higher insurance premiums.
Interest and Finance Costs
Interest and finance costs amounted to $21.8 million for the nine months ended December 31, 2020, a decrease of $6.0 million, or 21.4%, from $27.8 million for the nine months ended December 31, 2019. The decrease of $6.0 million during this period was due to a decrease of $8.1 million in interest incurred on our long-term debt, primarily resulting from a reduction of average indebtedness, lower LIBOR rates, and a reduced margin from the refinancing of the Commercial Tranche of the 2015 Facility, partially offset by an increase of $1.8 million in amortization of deferred financing fees, mainly due to accelerated amortization of $2.1 million related to the refinancing of the Cresques and the refinancing of the Original Commercial Tranche during the nine months ended December 31, 2020. Average indebtedness, excluding deferred financing fees, decreased from $691.9 million for the nine months ended December 31, 2019 to $640.6 million for the nine months ended December 31, 2020. As of December 31, 2020, the outstanding balance of our long-term debt, net of deferred financing fees of $11.1 million, was $603.9 million.
Unrealized Gain/(Loss) on Derivatives
Unrealized gain on derivatives was $4.0 million for the nine months ended December 31, 2020, compared to an unrealized loss $5.3 million for the nine months ended December 31, 2019 The favorable $9.3 million difference is primarily attributable to an increase of $8.3 million in favorable fair value changes to our interest rate swaps resulting from changes in forward LIBOR yield curves and an increase of $1.0 million in favorable fair value changes to our FFA positions.
Realized Gain/(Loss) on Derivatives
Realized loss on derivatives was $3.7 million for the nine months ended December 31, 2020, compared to a realized gain of $2.2 million for the nine months ended December 31, 2019. The unfavorable $5.9 million change is primarily attributable to (1) fluctuations in floating LIBOR resulting in a $5.1 million unfavorable variance on realized losses in the current period on our interest rate swaps and (2) unfavorable settlements of $0.8 million on our FFA positions.