Navigation Rules and Fault After a Vessel Collision

Boaters describe collisions in terms of right of way, and the rules do not use the phrase. They assign roles — one vessel gives way, the other stands on — and they impose on both an overriding duty to do whatever is necessary to avoid a collision. That structure is why fault is almost always shared.

One set of rules, two versions

Conduct between vessels is governed by a single consolidated body of navigation rules, with an inland version and an international version that differ in limited respects. The demarcation lines between them are charted, and the practical differences concern sound signals, certain lights and a handful of overtaking provisions.

Three rules do most of the work in ordinary casualties:

• Lookout. Every vessel must at all times maintain a proper lookout by sight and hearing, and by all available means appropriate to the conditions.
• Safe speed. Every vessel must proceed at a speed at which it can take proper and effective action to avoid collision and stop within a distance appropriate to the circumstances.
• Risk of collision. Every vessel must use all available means to determine whether risk exists, and must assume it does if there is any doubt.

These are not background principles. They are the provisions most frequently found to have been breached, and they apply to the vessel that had the stand-on role just as much as to the other.

Give-way and stand-on

The give-way vessel must take early and substantial action, clearly apparent to the other vessel — a series of small adjustments is specifically what the rules discourage. The stand-on vessel holds course and speed so that its behavior is predictable, but that duty converts: when it becomes apparent the give-way vessel is not acting, the stand-on vessel may act, and when collision cannot be avoided by the give-way vessel alone, it must.

How fault is divided

Maritime law once divided damages equally whenever both vessels were at fault, regardless of how unequal the fault was. That rule has been replaced by comparative apportionment: liability is divided in proportion to each vessel's contribution to the casualty.

Sitting on top of that is a presumption that decides many cases. Where a vessel is shown to have been in breach of a statutory rule at the time of a collision, the breach is presumed to have contributed, and that vessel must show the breach could not have caused it. Establishing that negative is difficult, which is why cases turn so heavily on breaches that look procedural — an absent lookout, unlit navigation lights, excessive speed in restricted visibility.

What happens in the minutes and days after

1. Render assistance to anyone in danger, so far as it can be done without serious danger to your own vessel and passengers. This duty is immediate and independent of fault.
2. Exchange identification — name, address and vessel identification — with the other operator.
3. Report the casualty where injury, death, disappearance or damage above the threshold is involved, within the deadline, which is shortest where there is a fatality.
4. Record the scene. Photographs, positions, weather, visibility, and the names of everyone aboard both vessels.
5. Notify the insurer promptly, and before discussing responsibility with anyone else.

Assistance arriving alongside a damaged vessel is its own decision, taken badly under pressure. A boat holed at the waterline and drifting is in exactly the condition that supports a salvage claim rather than a towing charge, and the operator who accepts a line without saying anything has agreed to whichever characterization the assisting party later advances — the distinction between a tow and a salvage is settled before the line is passed, not afterwards.

Where impairment is suspected, a separate investigation runs alongside the collision analysis, and the testing and refusal rules apply from the moment the officer has grounds. Impairment does not establish fault for the collision by itself, but it feeds the presumption analysis and it frequently affects insurance cover.

The claim, and who it runs against

Damage claims between recreational vessels are usually resolved between insurers on the apportionment above. Two features of maritime law can change the arithmetic on larger vessels: a shipowner's ability in some circumstances to limit liability to the value of the vessel after the casualty, and the availability of a maritime lien against the offending vessel, which allows a claim to be enforced against the boat itself rather than only against its owner. Where the vessel is federally documented and carries a preferred mortgage, the ranking between that mortgage and the collision claim decides who is paid from a forced sale, and it is not decided by the order in which the two arose.

Two liabilities sit outside the collision claim entirely and are frequently larger than it. The first is the wreck: an owner whose vessel sinks in a navigable channel can be required to mark it immediately and to remove it, and the removal cost falls on the owner regardless of who caused the casualty. The second is discharge. Fuel released from a ruptured tank triggers a federal pollution regime that operates on strict liability, with reporting obligations that run in hours rather than days and cleanup costs assessed against the responsible party before any question of fault is reached.

Equipment failures are the other recurring dispute, and they connect back to inspection: a vessel found without required equipment faces both a regulatory penalty and, where the missing item is relevant, an argument that its absence contributed to the harm.