During the first quarter 2022, we restarted 10 additional ships, resulting in 60% of our fleet capacity in guest cruise operations for the whole of the first quarter.
This was a substantial increase from 47% during the fourth quarter 2021.
As of today, 75% of our fleet capacity has resumed guest cruise operations.
And we now expect each brand's full fleet to be back in guest cruise operations for its respective summer season where we historically generate the largest share of our operating income.
For the first quarter, occupancy was 54% across the ships in service.
However, we had anticipated first quarter occupancy would exceed the 58% achieved in the fourth quarter of 2021.
We started the quarter with over 55% cabin occupancy booked for the first quarter and expected to improve upon that during the quarter.
All of this inhibited our ability to build on our cabin occupancy book position for the first quarter 2022 during the first quarter, resulting in occupancy for the first quarter 2022 at 54% being lower than the 58% occupancy we achieved in the fourth quarter of 2021.
Despite all that, during the first quarter, we carried over one million guests, which was nearly a 20% increase from the fourth quarter 2021.
Revenue per passenger day for the first quarter 2022 increased approximately 7.5% compared to a strong 2019 despite our lucrative world cruises and exotic voyages being shelved this year.
Over the past 2.5 years, we have offered and our guests have chosen more and more bundled package options.
On the cost side, our adjusted cruise cost without fuel per available lower berth day, or ALBD as it is more commonly called, for the first quarter 2022 was up 25%.
The increase in adjusted cruise costs without fuel per ALBD is driven essentially by five things: first, the cost of a portion of the fleet being in pause status; second, restart related expenses; third, 15 ships being in dry dock during the quarter, which resulted in nearly double the number of dry dock days during the first quarter versus the first quarter 2019; fourth, the cost of maintaining enhanced health and safety protocols; and finally, inflation.
We anticipate that many of these costs and expenses driving adjusted cruise costs without fuel per ALBD higher will end during 2022 and will not reoccur in 2023.
As a result of all of the above, we expect to see a significant improvement in adjusted cruise costs, excluding fuel per ALBD, from the first half of 2022 to the second half of 2022 with a low double-digit increase expected for the full year 2022 compared to 2019.
We ended the first quarter 2022 with $7.2 billion in liquidity versus $9.4 million at the end of the fourth quarter.
The change in liquidity during the quarter was driven essentially by four things: first, an improved negative adjusted EBITDA of $1 billion due to our ongoing resumption of guest cruise operations despite the impact of the omicron variant.
Second, our investment of $400 million in capital expenditures net of export credits.
Third, $500 million of debt principal payments.
And fourth, $400 million of interest expense during the quarter.
Since the middle of January, we have seen an improving trend in booking volumes for future sailings.
Recent weekly booking volumes have been higher than at any point since the restart of guest cruise operations.
We continue to expect that occupancy will build throughout 2022 and return to historical levels in 2023.
Our cumulative advanced book position for the first half of 2023 continues to be at the higher end of the historical range, also at higher prices with or without FCCs normalized for bundled packages as compared to 2019 sailings.
However, as I've already said, adjusted EBITDA over the first half of 2022 has been or will be impacted by the restart-related spending and dry dock expenses as 39 ships, over 40% of our fleet, will have been in dry dock during the first half of fiscal 2022.
Given all these factors combined, we expect monthly adjusted EBITDA to continue to improve and turn consistently positive at the beginning of our summer season.
We continue to expect a net loss for the second quarter of 2022 on both a U.S. GAAP and adjusted basis.
However, we expect the profit for the third quarter of 2022.
Looking to brighter days ahead in 2023, with the full fleet back in service all year, 8% more capacity than 2019 and improved fleet profile with nearly a quarter of our capacity consisting of newly delivered ships, continuing momentum on our outstanding Net Promoter Scores and occupancy returning to historical levels, we are looking forward to providing memorable vacation experiences to nearly 14 million guests and generating potentially greater adjusted EBITDA than 2019.

Summary:
As of today, 75% of our fleet capacity has resumed guest cruise operations.
And we now expect each brand's full fleet to be back in guest cruise operations for its respective summer season where we historically generate the largest share of our operating income.
Despite all that, during the first quarter, we carried over one million guests, which was nearly a 20% increase from the fourth quarter 2021.
Revenue per passenger day for the first quarter 2022 increased approximately 7.5% compared to a strong 2019 despite our lucrative world cruises and exotic voyages being shelved this year.
We anticipate that many of these costs and expenses driving adjusted cruise costs without fuel per ALBD higher will end during 2022 and will not reoccur in 2023.
As a result of all of the above, we expect to see a significant improvement in adjusted cruise costs, excluding fuel per ALBD, from the first half of 2022 to the second half of 2022 with a low double-digit increase expected for the full year 2022 compared to 2019.
We ended the first quarter 2022 with $7.2 billion in liquidity versus $9.4 million at the end of the fourth quarter.
Since the middle of January, we have seen an improving trend in booking volumes for future sailings.
Recent weekly booking volumes have been higher than at any point since the restart of guest cruise operations.
We continue to expect that occupancy will build throughout 2022 and return to historical levels in 2023.
Our cumulative advanced book position for the first half of 2023 continues to be at the higher end of the historical range, also at higher prices with or without FCCs normalized for bundled packages as compared to 2019 sailings.
Given all these factors combined, we expect monthly adjusted EBITDA to continue to improve and turn consistently positive at the beginning of our summer season.
We continue to expect a net loss for the second quarter of 2022 on both a U.S. GAAP and adjusted basis.
However, we expect the profit for the third quarter of 2022.