In accordance with rule 28 of the 72 COLREGS a vessel 'constrained by her draft' shall display 3 red lights vertically in addition to other navigation lights.
Please see the link provided below.
Cylinder. Think of a can, like a beer can hoisted up the mast. Some people remember "Can of draft beer".
From the 72 COLREGS, Navigational Rules of the Road. InternationalGeneralRule 3 (h)the term "vessel constrained by her draft" means a power driven vessel which, because of her draft in relation to the available depth and width of the navigable water is severelyrestricted in her ability to deviate from the course she is following.This is an International Rule. It has NO bearing in the US Inland rules.A vessel who cannot alter course due to the draft (the distance from the waterline to the keel) of her hull. For example if the draft is 10ft and on her current course the water depth is 11 ft but to the port and starboard of her the water depth is 5 ft. she is thus constrained to that course (she cannot deviate from it) because of her draft. She will display a day shape in the form of a can or cylinder, it can resemble a can of beer, remember a "draft of beer" and 3 red all round lights at night.
The most typical and obvious answer is on the Port (Left) side of the vessel. However there are more red lights dealing with the navigational lights on a vessel. Depending on the location and placement they could be lights for a vessel not under command, a vessel constrained by her draft and a vessel aground. A pilot boat and a sailing vesselwill display red lights in a different fashion.Rules 25,26,27,28,29 & 30 are helpful.In order to learn more refer to in the 1972 International Convention for Preventing Collisions at Sea (72COLREGS or Rules of the Road) link provided below.
Arrival draft means the deepness of the vessel under water when the cargo is loaded in the vessel, and departure draft means the deepness of the vessel under water after the cargo is discharged fully or partially.
Rules of the RoadRule 35Sound Signals in Restricted Visibility(C) A vessel not under command, a vessel restricted in her ability to maneuver, a vessel constrained by her draft, a sailing vessel, a vessel engaged in fishing, and a vessel engaged in towing or pushing another vessel shall..........sound at intervals of not more than two minutes, three blast in succession, namely one prolonged followed by two short blasts.
The draft of a yacht or any other vessel is the depth from the waterline to the lowest point of the keel. Naturally it varies with the vessel being considered.
If you are on a stand-on vessel, the exception that requires you to give way is when you encounter a vessel that is restricted in its ability to maneuver, such as a vessel engaged in fishing or a vessel constrained by its draft. In these situations, the stand-on vessel must yield to ensure safety and prevent collisions. Additionally, if the other vessel is not maintaining a safe distance or is on a collision course, it may also necessitate that you take evasive action. Always prioritize safety and navigation rules based on the specific circumstances.
Rules of the Road.Rule 35InternationalSound Signals in Restricted visibility.(c) A vessel not under command, a vessel restricted in her ability to maneuver, a vessel constrained by her draft, a sailing vessel, a vessel engaged in fishing, and a vessel engaged in towing or pushing another vessel shall, instead of the signals prescribed in paragraphs (a) or (b) of this rule, sound at intervals of not more than two minutes three blast in succession, namely one prolonged followed by two short blast.
A boat operator should alter their course and keep clear of another vessel when overtaking another vessel, when navigating in narrow channels where the other vessel has the right of way, or when approaching a vessel that is restricted in its ability to maneuver. Additionally, if another vessel is displaying any signals indicating it is constrained by draft or operating under sail, the boat operator should take measures to avoid a collision. It's essential to prioritize safety and adhere to navigation rules.
When two motor vessels are on a collision course, the vessel that has the other on its starboard side must give way. Motor driven vessels must also give way to vessels under sail unless constrained by draft in a narrow channel.
In any encounter between two "vessels," there is a "give-way" vessel and a "stand-to" vessel. The "give-way" vessel is the one that lets the "stand-to" vessel. IOW the "stand-to" vessel has the right-of-way. This is the "pecking order" of vessels: Vessels not under command Vessels restricted in their ability to maneuver Vessels constrained by draft Fishing vessels engaged in fishing, with gear deployed Sailing vessels Power-driven vessels Notice something? As you go down the list, the vessels become more and more maneuverable. A vessel constrained by draft - a ship that has to run in a dredged channel so it won't bottom-out - is less maneuverable than a sailboat, and a sailboat is less maneuverable than a motorboat. So...ASSUMING the two vessels are going to cross paths in a way that could cause a collision, the sailboat would be the stand-to vessel and the motorboat the give-way vessel. If the sailboat's path doesn't cross the motorboat's path or the motorboat's going to cross 20 miles in front of the sailboat, you don't have to do anything.
The design draft of a vessel refers to the vertical distance between the waterline and the bottom of the hull (keel) when the vessel is loaded. It indicates how deep the ship sits in the water and is crucial for ensuring stability, buoyancy, and compliance with port and navigation regulations. The draft can vary based on the vessel's cargo load and design specifications, influencing its performance and operational limitations. Understanding the draft is essential for safe navigation and docking in various water conditions.