Marine Survey Score Calculator
Calculate a composite condition assessment score for pre-purchase or periodic marine surveys.
About this calculator
This calculator produces a single composite condition score from six subjective 1-10 ratings a surveyor or owner assigns to a vessel's hull, engine, electrical systems, safety equipment, rigging/deck, and interior/systems. It is not a reproduction of any single named industry rubric -- professional marine surveys conducted by NAMS- or SAMS-accredited surveyors typically deliver a narrative condition-and-value report rather than a single published numeric weighting formula, and weighting choices vary by surveyor and vessel type. This calculator's own weighting gives Hull & Structure the largest share (30%) and Engine & Propulsion the next largest (25%), reflecting that hull integrity and propulsion reliability are the most expensive and safety-critical systems to fix, while Interior & Systems carries the smallest share (5%) because cosmetic and comfort items rarely affect seaworthiness or insurability.
The Overall Score is scaled to 100, and Est. Repair Cost is a rough percentage-of-value estimate derived directly from how far the score falls short of 100 -- it is not an appraisal and does not reflect actual parts or labor pricing. This calculator's own Insurance Eligible flag treats 60 as a cutoff; real insurers set their own underwriting thresholds and this should not be read as any specific carrier's requirement.
Inputs
Results
Overall Score
68 / 100
How to Use This Calculator
- Rate each of six systems (hull, engine, electrical, safety equipment, rigging/deck, interior) from 0-10.
- Higher scores represent better condition — use recent survey reports or direct inspection.
- Review the overall score out of 100 and the condition rating out of 5.
- Check the estimated repair cost percentage — values above 20% may affect insurance eligibility.
- A score below 60/100 typically makes a vessel ineligible for standard marine insurance.
How the result changes with Hull & Structure
| Hull & Structure | Overall Score |
|---|---|
| 3.5 | 57.5 / 100 |
| 5.25 | 62.7 / 100 |
| 10 | 77 / 100 |
What each input means
- Hull & Structure
- Hull integrity, plating thickness, corrosion, osmosis. 10 = new condition.
- Engine & Propulsion
- Engine hours, compression, running temperature, transmission, prop condition.
- Electrical Systems
- Wiring, panels, batteries, alternator, shore power, bonding.
- Safety Equipment
- Fire extinguishers, flares, life rafts, bilge alarms, navigation lights.
- Rigging & Deck
- Standing/running rigging, deck hardware, hatches, ports, caulking.
- Interior & Systems
- Plumbing, HVAC, galley, head, upholstery, woodwork.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersHull & Structure = 7, Engine & Propulsion = 7, Electrical Systems = 6, Safety Equipment = 7 = 6 input(s) provided
- Calculate Overall ScoreOverall Score68 = 68
- Calculate Condition RatingCondition Rating3 = 3
- Calculate Est. Repair CostEst. Repair Cost16 = 16
Engine last updated . Checked against 2 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Is the 30/25/15/15/10/5 weighting an official marine survey standard?
No -- it's this calculator's own weighting, not a published rule from NAMS, SAMS, or any insurer. Real marine surveyors typically deliver a narrative report rather than a single numeric formula, and how heavily they weigh hull versus engine versus other systems varies by surveyor, vessel type, and the purpose of the survey (insurance, financing, or pre-purchase).
Why does Hull & Structure move the Overall Score more than Interior & Systems does?
Hull & Structure carries this calculator's largest weight (30%) while Interior & Systems carries its smallest (5%), so identical changes to each rating produce very different swings in the Overall Score -- moving Hull & Structure by a full point moves the score six times as much as moving Interior & Systems by the same point. That reflects hull integrity being the most expensive and safety-critical system to get wrong.
Does a low score in one category always tank the Overall Score?
Not necessarily -- because the Overall Score is a weighted average across all six categories, a poor rating in a low-weighted area like Interior & Systems (5%) has much less impact than the same poor rating in Hull & Structure (30%). The Weakest Area Score output flags whichever category rated lowest so a single bad category isn't hidden inside a decent-looking average.
What does the Est. Repair Cost percentage actually represent?
It's a rough heuristic -- half a percentage point of estimated repair cost for every point the Overall Score falls below 100 -- not a quote, appraisal, or contractor estimate. A vessel scoring 70/100 shows roughly 15% of its value in estimated repairs under this calculator's formula, but actual repair costs depend on the specific defects found, vessel size, and local labor rates.
Related Calculators
The questions that sit next to this one — chosen by subject, including calculators filed under a different category.
Marine Insurance Premium Calculator
Estimate hull and P&I insurance premiums from vessel value, age, and trade area risk.
Commercial MarineVoyage Cost Calculator
Calculate total voyage cost including fuel, port, canal, crew, and insurance expenses.
Recreational BoatingBoat Survey Cost Calculator
Pre-purchase survey cost from boat type and length.
Auto RepairUsed Car Inspection Checklist Calculator
Inspection score and expected issues cost.
Commercial MarineBallast Water Exchange Calculator
Calculate ballast exchange volume, time, and compliance for BWM Convention requirements.
More in Aviation, Marine & Transport.