SEACOR Marine Holdings Inc.
US ˙ NYSE ˙ US78413P1012

SecuritySMHI / SEACOR Marine Holdings Inc.
InstitutionFirst Manhattan Co
Latest Disclosed Ownership320,585 shares
Latest Disclosed Value $ 2,295,389
First Manhattan Co reports 15.36% decrease in ownership of SMHI / SEACOR Marine Holdings Inc.

On May 15, 2026 - First Manhattan Co filed a 13F-HR form disclosing ownership of 320,585 shares of SEACOR Marine Holdings Inc. (US:SMHI) valued at $2,295,389 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 378,745 shares of SEACOR Marine Holdings Inc.. This represents a change in shares of -15.36% during the quarter. The current value of the position is $2,301,800 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F SEACOR MARINE HLDGS COM 78413P101 320,585 -58,160 -15.36 2,295 0.66 0.0064
2026-02-17 2025-12-31 13F SEACOR MARINE HLDGS COM 78413P101 378,745 -21,750 -5.43 2,280 -12.27 0.0060
2025-11-14 2025-09-30 13F SEACOR MARINE HLDGS COM 78413P101 400,495 7,500 1.91 2,599 29.69 0.0069
2025-08-14 2025-06-30 13F SEACOR MARINE HLDGS COM 78413P101 392,995 36,530 10.25 2,004 11.15 0.0057
2025-05-15 2025-03-31 13F SEACOR MARINE HLDGS COM 78413P101 356,465 5,100 1.45 1,804 -21.74 0.0053
2025-02-14 2024-12-31 13F SEACOR MARINE HLDGS COM 78413P101 351,365 101,285 40.50 2,305 -4.52 0.0068
2024-11-14 2024-09-30 13F SEACOR MARINE HLDGS COM 78413P101 250,080 80,775 47.71 2,413 5.69 0.0072
2024-08-15 2024-06-30 13F/A-1 SEACOR MARINE HLDGS COM 78413P101 169,305 0 0.00 2,284 -3.26 0.0073
2024-08-14 2024-06-30 13F SEACOR MARINE HLDGS COM 78413P101 169,305 0 2,284 0.0073
2024-05-15 2024-03-31 13F SEACOR MARINE HLDGS COM 78413P101 169,305 -6,112 -3.48 2,360 6.88 0.0076
2024-02-13 2023-12-31 13F SEACOR MARINE HLDGS COM 78413P101 175,417 -1,308 -0.74 2,208 -9.95 0.0077
2023-11-14 2023-09-30 13F SEACOR MARINE HLDGS COM 78413P101 176,725 -25,750 -12.72 2,453 5.96 0.0091
2023-08-14 2023-06-30 13F SEACOR MARINE HLDGS COM 78413P101 202,475 -26,615 -11.62 2,314 32.76 0.0085
2023-05-15 2023-03-31 13F SEACOR MARINE HLDGS COM 78413P101 229,090 -104,400 -31.31 1,743 -42.93 0.0067
2023-02-14 2022-12-31 13F SEACOR MARINE HLDGS COM 78413P101 333,490 -63,025 -15.89 3,055 37.07 0.0112
2022-11-14 2022-09-30 13F SEACOR MARINE HLDGS COM 78413P101 396,515 30,925 8.46 2,228 5.84 0.0094
2022-08-15 2022-06-30 13F SEACOR MARINE HLDGS COM 78413P101 365,590 -41,110 -10.11 2,105 -35.86 0.0085
2022-05-16 2022-03-31 13F SEACOR MARINE HLDGS COM 78413P101 406,700 -31,151 -7.11 3,282 120.56 0.0107
2022-02-14 2021-12-31 13F SEACOR MARINE HLDGS COM 78413P101 437,851 77,000 21.34 1,488 -10.90 0.0049
2021-11-15 2021-09-30 13F SEACOR MARINE HLDGS COM 78413P101 360,851 -16,499 -4.37 1,670 0.36 0.0062
2021-08-16 2021-06-30 13F SEACOR MARINE HLDGS COM 78413P101 377,350 45,000 13.54 1,664 -6.04 0.0061
2021-05-14 2021-03-31 13F SEACOR MARINE HLDGS COM 78413P101 332,350 -14,425 -4.16 1,771 88.60 0.0076
2021-02-16 2020-12-31 13F SEACOR MARINE HLDGS COM 78413P101 346,775 138,275 66.32 939 121.99 0.0045
2020-11-12 2020-09-30 13F SEACOR MARINE HLDGS COMMON 78413P101 208,500 2,800 1.36 423 -19.27 0.0022
2020-08-14 2020-06-30 13F SEACOR MARINE HLDGS COMMON 78413P101 205,700 98,300 91.53 524 11.49 0.0030
2020-05-06 2020-03-31 13F SEACOR MARINE HLDGS COMMON 78413P101 107,400 22,000 25.76 470 -60.07 0.0030
2020-02-13 2019-12-31 13F SEACOR MARINE HLDGS COMMON 78413P101 85,400 4,000 4.91 1,177 15.05 0.0059
2019-11-13 2019-09-30 13F SEACOR MARINE HLDGS COMMON 78413P101 81,400 -17,850 -17.98 1,023 -31.06 0.0056
2019-08-16 2019-06-30 13F SEACOR MARINE HLDGS COMMON 78413P101 99,250 -7,915 -7.39 1,484 4.07 0.0082
2019-04-12 2019-03-31 13F SEACOR MARINE HLDGS COMMON 78413P101 107,165 107,165 1,426 0.0082
2017-10-25 2017-09-30 13F SEACOR MARINE HLDGS COMMON 78413P101 0 -150 -100.00 0 -100.00
2017-08-10 2017-06-30 13F/A-2 SEACOR MARINE HLDGS COMMON 78413P101 150 150 3 0.0000
2017-08-01 2017-06-30 13F/A-1 SEACOR MARINE HLDGS COMMON 78413P101 150 0 3 0.0000
2017-07-28 2017-06-30 13F SEACOR MARINE HLDGS COMMON 78413P101 150 3 0.0000
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.