Length Overall

Not just one number.

Measure

Tracked in YachtPrep

Name	Length Overall (LOA)
Description	Overall length including overhangs
Allowed units	Meters (m) feet (ft)
Entities	Yacht Hull Plans Stability Book Yacht Registration Certificate

If you've ever tried to enter your yacht's details into management software, you've likely encountered a frustrating limitation: a single field for Length Overall (LOA). Enter one number and move on. Simple, right?

Not if you actually own a yacht.

The myth of the single LOA

For those outside the marine industry, LOA seems straightforward — it's just how long the boat is. But any experienced yacht owner, captain, or marine surveyor knows the reality is far more nuanced. Your yacht doesn't have one LOA. It has several:

Physical LOA

The actual measured length from the tip of the bow to the stern.
Declared LOA

What's listed on your registration documents.
Reported LOA

The measurement used for marina berth calculations.
Certified LOA

What appears on classification certificates.
Insurance LOA

The figure your underwriter has on file.

And here's where it gets interesting — these numbers are often different.

Why the discrepancy?

Different organisations measure LOA for different purposes, using different standards:

Marina berths

Marinas typically measure to the furthest point of the vessel, including bowsprits, swim platforms, and tender davits. This is what determines your berth fees and where you can dock.

Registration documents

Flag state authorities may use hull-only measurements or include specific appendages based on their regulations. A yacht registered in the Cayman Islands might show a different LOA than the same yacht under a different flag.

Classification societies

Lloyd's, RINA, or Bureau Veritas each have their own measurement protocols. These certificates are crucial for commercial operations and insurance.

Insurance policies

Underwriters may use the largest measurement for risk assessment or a standardised figure for premium calculations.

Race ratings

If you compete, your rating certificate will show yet another LOA based on specific racing rule measurements.

The real-world problem

Imagine this scenario: you're trying to book a berth at a new marina. They ask for your LOA. Which number do you give them?

The physical measurement? That might not account for your new swim platform. The registration figure? That could be outdated. The marina at your home port uses a different measurement altogether. Now multiply this confusion across every interaction: insurance renewals, charter agreements, refit planning, race entries, and international port clearances. Each requires an accurate LOA — but they don't all want the same number.

Contextual data modelling

The solution isn't to pick the "right" LOA — it's to model all of them with their proper context. Each LOA measurement should be stored with:

Context	Purpose
The source	Where did this measurement come from?
The purpose	What is this measurement used for?
The date	When was it recorded?
The authority	Which organisation provided or certified it?
The method	How was it measured?

This contextual approach means you always have the right number for the right situation. Need your registration LOA for a port clearance? It's there with the document reference. Marina asking for the docking length? You have that too, with the appendages included.

Beyond LOA: a broader pattern

This LOA challenge illustrates a broader truth about yacht management software: reality is almost always more complex than a simple form field assumes. The same pattern applies to:

Beam measurements — varies with tender stowage configuration
Draft figures — changes with load and fuel levels
Gross tonnage — different calculations for different purposes
Engine hours — multiple engines, different service intervals
Crew certifications — valid in some jurisdictions but not others

Software that acknowledges this complexity doesn't just store data better — it helps you manage your yacht more effectively.