Ship underwater surveys are an essential part of a ship’s maintenance program. These surveys are carried out to assess the condition of the underwater hull and other parts of the ship that are submerged in water. The purpose of these surveys is to identify any damage or defects that may be present and to determine the extent of any repairs or maintenance that may be required.

In-water surveys are carried out while the ship is afloat. These surveys are typically performed by divers or by using remotely operated vehicles (ROVs) equipped with cameras and other sensors. In-water surveys are less expensive and less time-consuming than dry-dock surveys, but they are limited in scope and may not be able to identify all types of defects.

Dry-dock surveys are carried out when the ship is dry-docked for maintenance or repairs. During these surveys, the ship is taken out of the water, and the hull is inspected by a team of experts. Dry-dock surveys are more comprehensive than in-water surveys and can identify more types of defects, but they are more expensive and time-consuming.

Ship underwater surveys are typically carried out in accordance with international regulations, such as the International Association of Classification Societies (IACS) requirements. These regulations specify the frequency, scope, and methods of the surveys. The frequency of the surveys depends on various factors, such as the age of the ship, the type of ship, and the operating conditions.

During an underwater survey, the survey team will inspect the hull and other submerged parts of the ship for any signs of damage or defects, such as cracks, corrosion, or marine growth. The survey team may also use non-destructive testing (NDT) techniques, such as ultrasonic testing or magnetic particle testing, to detect hidden defects.

Based on the results of the survey, the survey team will provide a report that outlines the condition of the ship and any repairs or maintenance that may be required. The ship’s owner or operator can use this report to plan and schedule any necessary repairs or maintenance activities.

In summary, ship underwater surveys are an important part of a ship’s maintenance program, and they help to ensure the safety and reliability of the ship. These surveys should be carried out regularly and in accordance with international regulations to maintain the integrity of the ship’s underwater hull and other submerged parts.