SHIP TRIM EXPLAINED | Why a Ship Doesn't Always Float Level

A ship doesn't always sail on an even keel. Depending on cargo distribution, ballast water, and operational requirements, the vessel may be trimmed by the stern or by the bow.

Here's a quick breakdown:

Trim by Stern
The aft draft is greater than the forward draft, meaning the stern sits deeper in the water.

Trim by Bow
The forward draft is greater than the aft draft, meaning the bow sits deeper in the water.

Even Keel
The forward and aft drafts are equal, so the ship floats level.

Trim Formula:
Trim = Aft Draft - Forward Draft

Why does trim matter?

• Improves fuel efficiency
• Optimizes propeller and rudder performance
• Enhances vessel handling and maneuverability
• Supports cargo safety and stability
• Helps ensure compliance with operational draft requirements

Understanding ship trim is essential for safe, efficient, and economical vessel operations.