/ 
Today, we're looking at a rare but concrete case: an encounter with an amphibious vessel during a work phase, both on the water and on the beach. And the answer is not as simple as port tack versus starboard tack.
What exactly is an amphibious vessel?
It may be a military craft, a port service vessel, a marine works barge, or a vessel specialized in cable laying or coastal logistics.
Its distinctive feature is that it travels afloat, then comes to ground voluntarily on the beach or a slipway to load, unload or work. Some are equipped with wheels or retractable tracks, while others simply use their hulls for beaching.
In the work phase, maneuverability is often reduced. Variable draught, partially engaged propulsion, crew focused on shore operations. In short, this is no RIB for cruising.
On the water, priority to vessels with limited manoeuvring capacity
The International Regulations for Preventing Collisions at Sea (RIPAM) apply.
An amphibious vessel in operation may be considered as a vessel with restricted manoeuvring capacity, as defined in RIPAM regulation 3, if it is limited by the nature of its work. In this case, it must display the corresponding lights and markings, three superimposed red, white and red lights, or the day markings ball, diamond, ball.
Faced with such a vessel, you need to step aside and maneuver decisively so as not to interfere with its work. Even if you have priority in a classic passing situation, the rule of caution prevails. And if the marks are not clearly visible, RIPAM rule 2 reminds us that all vessels must act with caution and good seamanship.
When approaching the beach, beware of restricted areas
The most delicate case remains the approach to or departure from a beach. An amphibious vessel can cross the 300-meter strip, a restricted zone where speed is limited to 5 knots and navigation is regulated.
If it is grounding or desludging, it is difficult for it to change its trajectory. Priority is then given to the maneuvering vessel, especially if the operation is supervised by port or maritime authorities.
For you, the boater, the instructions are clear: slow down, observe, keep your distance and never pass between the vessel and the beach. And don't forget that divers, cables or submerged devices may be present around the vessel.
On the beach, the sea is no longer the only rule
Once partially grounded, the amphibious vessel is located at the boundary between sea and land.
The rules of the road are no longer governed by a boating license, but by local regulations, often under the authority of the mayor or site manager. For yachtsmen in dinghies or paddles, the area should be considered as a construction site. You'll need to steer well clear of the area, avoid running propellers and stay out of reach of winching or ramping manoeuvres.
There's no arguing with the priority of operational safety.
What you need to know for your license
First rule: identify whether the ship is in operation. Lights, markings, visible activity on deck or ashore.
The second rule of thumb is to consider an amphibious craft in operation as a vessel with restricted manoeuvrability. You have to get out of the way.
Third rule: in the coastal strip, apply the maximum precautionary principle.
Such encounters are rare, but when they do happen, it's best to have a built-in reflex. At sea, as on a driving licence, priority is often given to the person who can manoeuvre the least.
