The Sea Urchin is a general break bulk cargo ship in Grand Theft Auto V.
The vessel is a small to medium sized general break bulk cargo ship. It has a marked forward draft but it is applied upside down so cannot be accurately recorded, but it would appear to be around 5-6 meters, and it has no aft draft markings. It has 24 rows of cargo access port on the main deck in sets of six, with the foremost set being a single row near the bow and then three sets of pairs of ports either side of the pair of deck mounted loading cranes.
It has a large superstructure with five levels above the deck with the bridge topmost. There is a radio and radar mast at the top of the superstructure and another radio mast at the bow. The exhaust stack is marked with a red and white striped livery with a distinctive large 5-point single silver star attached. There are two six-man lifeboats mounted on the third deck.
The hull is painted green with red below the Plimsoll Line. The bow is marked with a white painted US Air Force Roundel - a single 5-point star in a circle with three stripes marking wings either side and the name of the ship is painted in white on either side of the bow and in red on the stern. There is no home port of registration marked on the stern.
This ship isn't featured in any missions and plays no role in the storyline. Notably, while the deck levels of the superstructure are marked with windows, there are no hatches/doors present and the interior is completely inaccessible.
In GTA V, it can be found in Elysian Island near the Los Santos Naval Port. Combined with the vessel's military-style marking and paint scheme, this may imply some association with the private military forces of Merryweather Security.