Towing, Ice Navigation & Special Operations

It is a direct danger to navigation, so SOLAS V obliges the master to report it by all means available. To ships around me: a SECURITE call on VHF 16 then the working channel — nature of the danger, position, time. To the authority: the coastguard or nearest coast station, who will assess and promulgate it as a navigational warning — NAVTEX and, if warranted, a NAVAREA broadcast — so it reaches ships beyond my VHF range and eventually the emergency wreck-marking machinery if it stays afloat. My log gets position, time and description; my own track gets a wide berth around it; and if I can safely stand by to mark it while traffic is close, that's seamanship — but the REPORT is the obligation, and it goes out before anything else.

Call the Master. Confirm the nature of the casualty and obtain position, number of persons, and sea state. Notify MRCC of our intention to assist — clarify whether this is a duty-to-assist SOLAS situation or a commercial salvage, and whether Lloyd's Open Form applies. If LOF is relevant, obtain the casualty's agreement before passing the tow — the Master handles this, not the OOW. On deck: prepare the tow rope on our foredeck, led through the anchor hawse or bow fairlead and secured to the strongest forward bollards. Pass a heaving line to the yacht to lead the tow rope. Once the tow is connected on the yacht, ensure they have made it fast to their strongest bow fitting — not a cleat. Add chafing gear at all fairleads. The yacht must have a helmsman on the wheel. Apply power very slowly — do not snatch the tow line. Set tow speed appropriate to sea state — typically 2–3 kn in moderate conditions. Maintain catenary in the tow line. Keep a watch on the tow line for chafe. The yacht's crew communicates with us by radio on an agreed channel. Log all actions and times. Maintain contact with MRCC throughout.

Ice accretion raises the centre of gravity because the weight is high up — on the superstructure, rigging, and upper decks. This reduces GM. In severe conditions ice can accumulate at rates that overwhelm the vessel's initial stability in a matter of hours. A vessel with significant topside icing in a beam sea can become dangerously tender. Immediate actions: call the Master; inform the engineer — we may need to fill low ballast tanks to lower the centre of gravity and restore GM; alter course to reduce the angle to the sea and reduce spray generation — this is the most effective immediate measure; reduce speed for the same reason; deploy all available crew to manually chip ice from decks, rigging, and superstructure — start with the highest points first; check bilges for meltwater accumulation and pump if needed; monitor the barograph and sea temperature — if conditions are worsening, we may need to alter course significantly to exit the icing zone. If the vessel develops a persistent list, do not correct with anti-heeling ballast alone — investigate the cause. Log all observations and actions.

The load line marks (Plimsoll marks) are permanently marked on both sides of the hull amidships. They show the maximum permitted draught in different sea areas and seasons. The main marks from top (shallowest draft permitted) to bottom are: TF — tropical fresh water; F — summer fresh water; T — tropical salt water; S — summer (the standard reference); W — winter; WNA — winter North Atlantic (for vessels under 100m only). As OOW I must know which zone we are in and which mark applies. Before departure I check the current draught against the applicable load line mark for the zone and season — the Plimsoll line must not be submerged. The Load Line Certificate (from the classification society) defines the zones and marks. Overloading is a statutory offence and a safety issue — excess draught reduces freeboard, reduces range of positive stability, and makes the vessel more vulnerable in heavy weather. The Chief Officer calculates departure stability and draught — I refer to their calculations and the certificate.