Dry Docking

What Is Dry Docking?

Dry docking is the process of taking a vessel out of the water by placing it in a dry dock — a narrow basin that can be flooded and then drained to allow the ship to rest on blocks with its hull fully exposed. This enables inspection, maintenance, and repair of all underwater parts of the vessel, including the hull plating, anti-fouling coating, sea chests, propeller, rudder, stern tube seal, and cathodic protection anodes.

Dry docking is one of the most significant and costly maintenance events in a vessel's operational life, typically required at intervals of two and a half to five years depending on the vessel's age, type, and classification society requirements.

Why Ships Need Dry Docking

Dry docking serves both regulatory and operational purposes. Classification societies require periodic underwater hull surveys that can only be performed with the vessel out of the water, unless alternative in-water survey arrangements are approved.

These surveys verify the structural integrity of the hull, the condition of the rudder and propeller, and the effectiveness of corrosion protection systems. Operationally, dry docking is essential for maintaining hull performance — marine growth (biofouling) on the hull increases frictional resistance, which directly increases fuel consumption.

A clean hull with fresh anti-fouling paint can reduce fuel consumption by 10-15 percent compared to a fouled hull, making dry docking a significant factor in both environmental performance and operating economics.

Planning and Cost Management

Effective dry dock planning begins months or even years before the vessel enters the dock. The technical superintendent develops a detailed specification of work that includes class-required surveys, owner's maintenance items, and any repair work identified during the vessel's service period.

Shipyard selection involves evaluating yard capabilities, geographic location relative to the vessel's trading pattern, pricing, and availability. Cost management is critical, as a typical dry docking can cost hundreds of thousands to several million dollars depending on the vessel size and scope of work.

Major cost components include dock rental, steel renewal, blasting and painting, propeller and rudder work, valve overhauls, and crew and superintendent travel expenses.

How Software Supports Dry Dock Projects

Vessel management software streamlines dry dock project management by providing tools for specification development, budget tracking, progress monitoring, and document management. Digital platforms enable technical superintendents to build standardized dry dock specifications from templates, track quotations from multiple shipyards, manage change orders during the dock period, and compare actual costs against budgets in real time.

Photo documentation, daily progress reports, and deficiency tracking can all be managed within the platform. Integration with the planned maintenance system ensures that dry dock-dependent maintenance jobs are automatically scheduled and their completion recorded, while integration with procurement manages the supply of spare parts, paints, and consumables required for the dry dock period.