The marine weighing knowledge centre
Practical, sourced guides on weighing at sea – motion compensation, legal metrology, onboard processing, research sampling, materials and data. Written for skippers, fleet managers, processors and scientists.
Weighing at Sea: The Complete Guide to Motion-Compensated Scales
Motion compensation, gravity and accuracy on a moving vessel
Open the complete guideWhy Ordinary Scales Fail on a Moving Vessel
Ordinary scales fail at sea because a load cell measures force, not mass. When the deck heaves, pitches or rolls, that force rises and falls with the deck's acceleration, so...
Read guideGetting Accurate Weights in Rough Seas: A Practical Checklist
Accurate weighing in rough seas starts with location: mount the scale close to amidships and the centreline, rigidly and level. Then match filter and stability settings to the job, zero...
Read guideMotion Compensation in Marine Scales: What It Does and How to Judge It
Motion compensation lets a marine scale show the true weight of a load while the deck heaves, pitches and rolls. Good compensation gives a steady reading, fast settling, and correct...
Read guideGravity, Latitude and Why Marine Scales Need Gravity Compensation
Gravity increases by about 0.53% from the equator (9.780 m/s²) to the poles (9.832 m/s²). A scale adjusted at 52° N reads about 0.14% heavy at 70° N: 21 g...
Read guideLegal Metrology at Sea: Weighing Rules for Fishing Vessels
EU fisheries control, OIML, NAWI/MID and verification
Open the complete guideOIML R51 vs R76: Which Standard Applies to Your Scale?
OIML R 76 applies to non-automatic weighing instruments, where an operator intervenes in each weighing, such as bench and platform scales. OIML R 51 applies to automatic catchweighing instruments that...
Read guideNAWI and MID Directives Explained for Marine Scale Buyers
The NAWI Directive 2014/31/EU covers non-automatic scales and is mandatory for regulated uses such as commercial transactions; the MID 2014/32/EU covers automatic weighing instruments where Member States prescribe them. Conforming...
Read guideEU Fisheries Control Regulation: What It Means for Weighing Catches
Since 10 January 2026, Article 60 of the EU Control Regulation requires all landed fishery products to be weighed per species immediately after landing, by an authorised operator, on systems...
Read guideCalibration, Verification and Re-verification of Marine Scales
Calibration measures how far a scale's indication deviates from reference weights, with an uncertainty. Verification is a legal conformity check that ends with a mark or certificate. Re-verification intervals are...
Read guideOnboard Fish Processing: Weighing, Grading and Labelling at Sea
Grading, batching, labelling and catch traceability
Open the complete guideWeight Grading Fish: How Graders Sort by Weight Class
A fish weight grader singulates pieces on an infeed belt, weighs each one on a short load-cell belt and diverts it to the outlet for its weight class. Accuracy depends...
Read guideReducing Giveaway: Batching Algorithms Explained
Giveaway is product packed above the declared weight. Filling a box piece by piece overshoots by roughly half an average fish. Batching algorithms reduce this by keeping several packs or...
Read guideLabelling Fish Boxes and Crates at Sea
A fish box label should carry the lot number, species with scientific name, production method, FAO catch area, gear category, net weight, date marking, storage conditions and operator, as required...
Read guideCatch Registration and Traceability from Haul to Harbour
Catch registration records species, catch area, gear, catch date and net weight for every lot, linked to the fishing trip. Since 10 January 2026, EU rules (Article 58 of Regulation...
Read guideWeighing for Fisheries Science and Marine Research at Sea
Biological sampling and precision weighing for science
Open the complete guidePrecision Weighing of Small Samples at Sea: Otoliths, Gonads and Stomach Contents
Choose a readability no larger than about 1 % of the lightest sample. At sea, a motion-compensated scale reading to 0.1 g with a wind cover suits gonads, livers and...
Read guideLength–Weight Relationships in Fish: What They Tell Scientists
A length–weight relationship predicts how heavy a fish of a given length should be. Weight rises roughly with the cube of length, so a fish 10% longer is about a...
Read guideChoosing a Scientific Marine Scale for a Research Vessel
Start from the samples: list each weighing task with its mass range and required resolution, then choose capacity, readability and platform per station. Check motion compensation under realistic conditions, stabilisation...
Read guideBiological Sampling on Research Vessels: The Weighing Workflow
On a fisheries survey the catch is sorted by species, each species or size category is weighed, a representative subsample is measured for length and raised to the whole category...
Read guideMarine Scale Construction: Stainless Steel, IP Ratings and Hygiene
Stainless steel grades, IP ratings and washdown
Open the complete guideAISI 304 vs 316 vs 316L: Which Stainless Steel Survives at Sea?
For equipment exposed to seawater spray and salt, 316 or 316L is the usual choice because 2-3 % molybdenum raises the pitting resistance number (PREN) to 24-26, against 18-20 for...
Read guideIP67, IP68 and IP69K Explained for Washdown Weighing
IP67 means dust-tight and protected against temporary immersion at 1 m for 30 minutes; IP68 means dust-tight and protected against continuous immersion under stated conditions; IP69K means dust-tight and protected...
Read guidePreventing Corrosion and Extending Scale Life at Sea
Marine scales usually corrode at details, not across whole surfaces. Prevent galvanic corrosion by insulating stainless steel from aluminium or carbon steel, avoid crevices under gaskets, tape and washers, keep...
Read guideCleaning and Washdown of Scales in Fish Processing
Clean scales in fish processing with a full cycle: remove residues, pre-rinse with cold water, apply an alkaline detergent for 10-15 minutes, rinse, disinfect and finish with a fresh-water rinse....
Read guideFrom Scale to Shore: Weighing Data, IoT and System Integration
Logging, APIs, interfaces and ship-to-shore data
Open the complete guideWeighing Data Logging at Sea: What to Record and Why
Log every weighing automatically with a unique ID, UTC timestamp, scale ID, preset, net weight, unit, stability and lot. Keep an audit trail of calibration and setting changes, calculate statistics...
Read guideShip-to-Shore Data: Connectivity Options for Fishing Vessels
Fishing vessels send data ashore via 4G/5G near the coast, L-band satellite services worldwide, GEO VSAT or LEO satellite broadband offshore, or by store-and-forward at port. Weighing data is tiny,...
Read guideRS232, Ethernet, USB, Wi-Fi or Bluetooth LE: Choosing a Scale Interface
Use Ethernet for permanent integration of scales and graders with software (100 m per segment), RS232 for short point-to-point links to printers and displays (about 15 m), USB for configuration...
Read guideIntegrating Scales with Your Software via an API
A scale API lets software read live weight, stability, presets and stored records, and send commands such as zero, tare and print, usually as JSON over the network. Use stable,...
Read guideHow to Choose a Marine Scale: A Buyer's Guide
Capacity, platform size, installation and cost of ownership
Open the complete guideTotal Cost of Ownership of a Marine Scale
The total cost of ownership of a marine scale is dominated by recurring costs, not the purchase. Giveaway from overfilling on unsteady readings, downtime at sea, recalibration, corrosion and manual...
Read guideChoosing the Platform Size for Fish Boxes, Baskets and Samples
Choose a platform that fully supports the base of your largest regular container, with nothing else touching it. Typical European fish boxes measure 600 × 400 mm (10–15 kg fillet...
Read guideInstalling a Marine Scale on Deck or in the Fish Hold
Install a marine scale close to amidships and the centreline, on a rigid wall or column mount fixed to structure, levelled at normal trim. Keep hoses and cables off the...
Read guideCapacity vs Readability: Choosing the Right Weighing Range
Capacity is the heaviest load a scale can weigh; readability is its smallest displayed step. Choose capacity from the heaviest gross load plus a margin for motion and impacts, then...
Read guideTell us what you weigh and where
Every vessel is different. Share your application and we will recommend a scale, platform size and options – with a no-obligation quote.