The Ledger Beneath the Hull

Challenge Summary

Challenge Scenario

Lord Damas Marrowcairn does not command fleets — he owns them through a labyrinth of paper. A single cargo vessel, the ASHEN MERCY, sits at the center of a web spun across five companies: a nominee-owned shell that holds the hull, a management firm that runs the machinery, a coordination house that directs the voyages, and a commodities trader that fills the holds. Each layer is clean. Each layer is someone else’s name. But every thread, if pulled hard enough, runs back to the same hand. The Outer Isles P&I Club has opened its registry for inspection — registry files, charter fixtures, company ledgers, and P&I entries are all available to those who know where to look. Reconstruct the full ownership chain. Prove that the hand beneath the ink belongs to Marrowcairn.

Use the Oath Submission form to confirm your findings, then assemble the flag from the verified answers.

Flag Format: HTB{ITEM_WAS_SHARED_AMONG_QUANTITY_TARGETS}

Flag Example: HTB{THE_WATER_WAS_RATIONED_AMONG_SIX_VILLAGES}

Challenge Info

Category	OSINT
Points	875
Difficulty	Easy
Creator	Joey
Release Date	2026/07/24

Solution

End Goal

Our challenge scenario states that our end goal is to reconstruct the full ownership chain.

Reconstruct the full ownership chain. Prove that the hand beneath the ink belongs to Marrowcairn.

The Court-Eaves Console

As with any OSINT challenge, we want to understand two things. The tools that are available and the questions that need to be answered.

Tools Provided

1. Briefing
2. Tideglass
3. Registry
4. P&I DIR
5. Charter
6. Companies
7. Evidence
8. Threadboard
9. Submit

Findings Submission

As we go through the investigation, keep these questions in the back of your mind.

1. Who is the vessel’s registered owner?
2. Who is the vessel’s ISM manager?
3. Which company is listed as the commercial operator?
4. Which company is the time charterer?
5. Which parent company ultimately control both the operator and the charterer?

Case Briefing

In our case briefing we’re given some data points to start connecting the dots.

From the briefing, the following data points stick out:

Vessel IMO	9724418
P&I Entry	PI-VAL-88291
Release Approver	Eastreach Maritime Coordination PLC

Maritime Registry

The Registry requires an IMO number, vessel name, or registry name. Right now, we only have the Vessel IMO number given in the briefing - 9724418.

Information Obtained from the Maritime Registry

Vessel Name	Ashen Mercy
MMSI	636019772
Radio Call Sign	D5MR8
Flag State / Register	Outer Isles Register
Vessel Type	General Cargo
Year Built	2014
Registry File	OIR-9724418-2026
Registered Owner	Thirteenth Tide Shipping Ltd
ISM Manager	Morrow Fleet Management SA
Technical Manager	Morrow Fleet Management SA

Then maritime registry provided more specific information we can use to track this vessel and the companies operating it. Looking back at our Evidence Satchel, we can see our finding is already populated.

We can also start to fill out the Threadboard:

The note at the bottom of the Maritime Registry states that this record does indicate commercial operation or charter arrangements and to consult the P&I Directory for operational details.

P&I Directory

Pivoting over to the P&I Directory. Here we can filter by entity number, IMO number, or vessel name. Let’s use the entity number (P&I Entry) provided in the briefing - PI-VAL-88291.

Information Obtained from the P&I Directory

Member / Registered Owner	Thirteenth Tide Shipping Ltd
Co-Assured	Morrow Fleet Management SA
Commercial Operator	Eastreach Maritime Coordination PLC
Time Charterer	Gilded Knife Commodities Ltd
Entry Period	2026-01-01 to 2026-12-31
Trading Area	Valyssar coast, Stormcoast, Northern Crown Road ports
Certificate Status	Active

The P&I Directory has provided more information about the companies operating the vessel Ashen Mercy, including the commercial operator and time charterer. Again, our Evidence Satchel has been populated with our new findings.

We can also add these additions to our Threadboard:

The analyst note at the bottom of the P&I Directory states the commercial operator and time charterer listed in this entry differ from the registered owner (Thirteenth Tide Shipping Ltd). It goes on to say “this is standard for time-chartered vessels operating under third party commercial management” and to investigate the corporate relationships between these companies.

Companies Register

The Companies Register allows us to look up information about all the companies we’ve discovered during this investigation.

Thirteenth Tide Shipping Ltd

Thirteenth Tide Shipping Ltd is a single-vessel company with the following identifiers

Company Number	OI-771204
Registered Office	80 Seaward House, Port Cinder
Directors	Nominee Maritime Directors Ltd
Shareholders	Morrow Nominee Holdings SA

Morrow Fleet Management SA

Morrow Fleet Management SA has the following identifiers

Company Number	ER-441902
Registered Office	14 Anchor Court, Eryndal
Directors	Deren Morrow and Sela Quill
Shareholders	Morrow Marine Group SA - 100%

Eastreach Maritime Coordination PLC

Eastreach Maritime Coordination PLC has the following identifiers

Company Number	ER-220014
Registered Office	3 Saltmarsh Lane, Eryndal
Directors	Damas Marrowcairn, Leven Orr, and Sera Dain
Shareholders	Marrowcairn Strategic Holdings PLC - 100%
Parent Company	Marrowcairn Strategic Holdings PLC

Gilded Knife Commodities Ltd

Gilded Knife Commodities Ltd has the following identifiers

Company Number	ER-220881
Registered Office	3 Saltmarsh Lane, Eryndal
Directors	Leven Orr
Shareholders	Marrowcairn Strategic Holdings PLC - 100%
Parent Company	Marrowcairn Strategic Holdings PLC

Both Eastreach Maritime Coordination PLC and Gilded Knife Commodities Ltd have the same parent company Marrowcairn Strategic Holdings PLC and have the same registered office of 3 Saltmarsh Lane, Eryndal. Both companies also list Leven Orr as one of their directors.

Marrowcairn Strategic Holdings PLC

Marrowcairn Strategic Holdings PLC has the following identifiers

Company Number	ER-009901
Registered Office	1 Crown Passage, Eryndal
Directors	Damas Marrowcairn
Shareholders	Damas Marrowcairn - 72% and Unnamed institutional investors - 28%

Our Evidence Satchel has been populated with our findings.

Let’s also update our Threadboard with our new findings:

Findings Submission

In Submit, we can use all the evidence gathered to submit the answers to the questions.

The hull belongs to a paper company. The machinery answers to a manager. The voyages answer to Eastreach. Beneath every layer sits the same hand, clean because the ink has been divided among five names.

Our task was to “prove that the hand beneath the ink belongs to Marrowcairn.” Throughout this challenge, we were able to use the Maritime Registry, P&I Directory, and the Companies Register to prove Marrowcairn Strategic Holdings PLC owns Eastreach Maritime Coordination PLC and Gilded Knife Commodities Ltd. Both of these companies operate and charter the Ashen Mercy vessel respectively.

The challenge scenario specified the flag format is: HTB{ITEM_WAS_SHARED_AMONG_QUANTITY_TARGETS}.

• The item that was shared was the ink.
• The ink was divided among five names (companies).

Putting the clues together in the quote, leaves us with the following flag: HTB{THE_INK_WAS_DIVIDED_AMONG_FIVE_NAMES}.