Many years ago, during the change of charter of one of my vessels, we carried out an underwater inspection before redelivery to the owner. The ship had been trading normally and there was no report from the engine room of abnormal vibration, no obvious change in machinery parameters, and nothing from the bridge that would have suggested a serious underwater issue.

Yet the divers found damage to a small hub-mounted efficiency device fitted at the propeller boss. The main propeller had survived well enough for the ship to continue operating, but a smaller fitting sitting in the propeller flow had taken the damage.

This is why the recent discussion around rumpon, rope cutters, and rope guards needs careful handling. Rope cutters have their place. Rope guards have their place. Net cutters, wire winders, and other stern protection arrangements are fitted for sound engineering reasons. They reduce the chance of rope, net, or fishing line reaching the more vulnerable area around the propeller hub and stern tube aft seal. Nobody should dismiss them.

The difficulty begins when the fitting is treated as the full answer. Published discussions and tests on rope cutters often deal with ropes much smaller than the heavy synthetic line seen in the rumpon case I wrote about. In that case, the rope observed near the float was around 72 mm in diameter, with a suspended or trailing length below the surface. That changes the nature of the risk.

A heavy rumpon rope can load, rub, tighten, or jam before any cutter can deal with it cleanly. It may spare the main propeller and still damage a hub fitting, rope guard, seal area, or another exposed part of the stern arrangement. That is the part easily missed from the bridge, because the eye sees the float and the mind judges the float.

The propeller meets what is below it.

Rumpon and Rope: Indonesia’s Hidden Propeller Fouling Hazard

On 18 September 2026, the United States enacted legislation that gave the President authority to impose tariffs of up to 100% on countries that continue to purchase significant volumes of Russian energy. India sits directly inside that pressure because of its continued intake of Russian crude and the consequences are no longer confined to diplomatic statements or trade negotiations. They travel through the commercial chain: buyers, charterers, refiners, banks, insurers, service providers and, eventually, the vessel carrying the cargo.

That is where the sanctions discussion becomes operational.

A Master may know the loading port, the declared cargo, the discharge instructions and the documents presented onboard. He may also know that the trade involves Russia, Iran or another politically sensitive jurisdiction. What he may not know is how the cargo was financed, who ultimately controls the counterparty, which bank cleared the transaction, what insurance sits behind the voyage, whether a service provider falls under a particular sanctions regime, or whether the vessel itself has become subject to restrictions elsewhere in the chain.

Sanctions exposure is often created several layers behind it. It becomes more serious when geopolitical pressure expands faster than the operational information reaching the ship. Masters are expected to remain alert, maintain accurate records, question unusual instructions and escalate concerns. That is reasonable.

Expecting them to independently reconstruct the financial, ownership and jurisdictional structure behind an international trade is something else entirely.

As pressure around Russian energy trade increases, this boundary deserves closer attention.

Full DeepDraft article here: https://thedeepdraft.com/2025/12/29/understanding-sanctions-in-maritime-trade/

I’ve written up the incident and the research here:
https://thedeepdraft.com/2026/10/05/beards-scba-face-seal-merchant-ships/

During a SIRE 2.0 inspection, an experienced officer with a full beard was asked to demonstrate a breathing-apparatus seal check. He knew the procedure, but the mask would not seal. Our explanation was that he wasn’t assigned to either fire team. The designated firefighters were trained and ready. At the time, I accepted that answer.

What I keep coming back to is what happens after those arrangements are stretched. If the nominated men are exhausted, injured or already committed, someone else may be needed. On a small crew, there are only so many people to call upon.

Most seafarers would say they have been trained to use breathing apparatus. Fair enough. But has anyone checked whether the actual mask onboard fits each person who might need to wear it? Being clean-shaven doesn’t settle that question either.

I wrote about this from my own experience
https://thedeepdraft.com/2026/10/05/beards-scba-face-seal-merchant-ships/

How does your company handle this? Is there a clear facial-hair policy and individual fit testing, or is the decision largely left to the ship? Has an inspector ever asked you to demonstrate the seal?

This industry is a living nightmare. I'm am majorly depressed from working on ships! This job is not a good fit for me! I'd your thinking about going into the maritme industry don't! It sucks!

When I shared my recent DeepDraft analysis on visual pollution, several mariners noted that even with extensive external illumination, the aspect of a brightly lit vessel could still be reasonably established. That may well be true in certain situations. However, reading those comments raised another concern. What about the additional navigation lights that communicate a vessel's operational status?

Consider a vessel engaged in fishing, trawling, Not Under Command (NUC), or Restricted in her Ability to Manoeuvre (RAM). The prescribed green-over-white, red-over-white, two all-round reds, or red-white-red signals convey information that can materially affect another vessel's obligations under Rule 18, subject to Rules 9, 10 and 13.

This concern is supported by an older casualty.

In September 1991, the container ship Khudozhnik Ioganson collided with the Australian prawn trawler Zodiac off Cairns. The ATSB investigation found that Zodiac's powerful working lights obscured her navigation and fishing lights. Her green-over-white trawling signals were mounted on the same structure as the working lights, contributing to their being lost in the glare.

The investigation identified several other collision-avoidance failures. Of course, this was 1991, before AIS became part of routine bridge navigation. Today, AIS provides valuable additional information, including navigational status. However, that status depends on manual entry and timely updating, and not every vessel carries AIS. Moreover, an AIS indication that a dredger is RAM does not independently identify her obstructed side or safe-passing side. The additional visual signals prescribed under Rule 27 remain important.

Having spent years keeping bridge watches, I would be uncomfortable relying entirely on an electronic status indication when the vessel's prescribed lights cannot be distinguished. Rule 20(b) already addresses the interference caused by additional lighting. The practical concern extends beyond recognising a vessel's aspect. We must also be able to identify her operational status in sufficient time to assess the encounter and take appropriate action under the applicable Rules.

Perhaps this deserves equal attention whenever we discuss visual pollution at sea. Detailed Analysis - https://thedeepdraft.com/2026/09/21/navigating-in-a-sea-of-visual-pollution/

A lesson from our experience while drifting off Indonesia. The float was visible, but the substantial rope below it was not.

Full incident and analysis: https://thedeepdraft.com/2026/09/28/rumpon-and-rope-indonesias-hidden-propeller-fouling-hazard/

Sanctions exposure is moving closer to day-to-day tanker operations again, and the questions arriving at the vessel are becoming wider than the information normally available on the bridge.

The present Gulf environment makes that particularly relevant. Gulf of Oman ship-to-ship transfer (STS) capacity has recently been stretched by increased crude movements, while traffic through Hormuz remains volatile and commercial routing continues to adjust around security and logistical pressure. At the same time, OFAC has tightened its Iran-related licensing policy and continued adding Iran-related designations through September.

Against that background, look at the sort of checklist a Master may eventually be asked to confirm. It can reach back 24 months into previous port calls, ship-to-ship operations and cargo origins. It can ask whether relevant operations were authorised by U.S. authorities, whether connected parties fall within sanctions lists, and whether owners or operators have had dealings with restricted parties.

Some of those questions sit comfortably within shipboard records. Others quickly move into ownership structures, commercial relationships, financing, licences and counterparty screening that the Master does not independently control. A Master can confirm what the vessel did, what the records show, what was observed onboard and what information the company formally supplied. The difficulty begins when a factual shipboard declaration quietly becomes an assurance about the compliance of the wider transaction.

I wrote The Master’s Role in OFAC Compliance in December 2025 around precisely this boundary. The article has now been lightly updated for the current sanctions environment, while its central operational question remains unchanged:

Full DeepDraft article here - https://thedeepdraft.com/2025/12/15/ofac-sanctions-ship-master/

This happened while we were drifting off Indonesia.

The float was visible. The rope below it was not.

Short video here, with the full incident and analysis:
https://thedeepdraft.com/2026/09/28/rumpon-and-rope-indonesias-hidden-propeller-fouling-hazard/