Independent marine surveyors & cargo inspection at U.S. ports
24/7 Survey Inquiries: 404-390-2132 | info@amicamarine.com
Independent marine surveyors & cargo inspection at U.S. ports
24/7 Survey Inquiries: 404-390-2132 | info@amicamarine.com
Initial and final draft surveys for bulk carriers at New Orleans, Houston, Corpus Christi, Mobile and other Gulf Coast ports, with independent readings, density checks and full calculation sheets.
A draft survey determines the weight of dry bulk cargo by measuring a vessel’s displacement before and after loading or discharge. Amica Marine surveyors read drafts, measure water density, sound ballast and deductible tanks, and calculate cargo weight from the vessel’s hydrostatic tables.
Amica Marine carries out draft surveys at U.S. ports for shippers, receivers, charterers, owners and their insurers. A draft survey is the standard method for establishing the weight of bulk cargo where shore scales are not available or where their figures need an independent check.
The principle is Archimedes’ law: a floating vessel displaces its own weight in water. By measuring how deep the vessel floats before and after cargo operations, correcting for the density of the water and for changes in ballast, fresh water, fuel and other variable weights, the surveyor calculates the weight of cargo loaded or discharged.
Draft surveys are used for grain, soybeans, coal, petroleum coke, iron ore, fertilizer, sulfur, cement, aggregates and many other dry bulk cargoes moving through Gulf Coast ports. The resulting figure often forms the basis of the bill of lading quantity, the commercial invoice or a shortage claim at the discharge port.
The survey is only as good as the readings and the vessel’s documents. Our reports therefore record every reading, every correction and every condition that could affect accuracy.
A draft survey is required when bulk cargo weight must be established independently: at loading to support the bill of lading quantity, at discharge to verify outturn, when shore scales are unavailable or disputed, and when a shortage or overage claim needs documented evidence.
Typical situations where an independent draft surveyor is appointed include:
Draft surveys should be planned before operations start. Once loading or discharge begins, the initial condition cannot be recreated, and the accuracy of the final figure depends on it.
The surveyor reads six drafts, forward, midship and aft on both sides, measures dock water density with a hydrometer, sounds all ballast, fresh water and fuel tanks, applies trim, hog or sag and density corrections, then compares initial and final displacement to obtain cargo weight.
Our draft survey method follows the widely used UN/ECE Code of Uniform Standards and Procedures for the Performance of Draught Surveys of Coal Cargoes, applied across dry bulk cargoes. A survey includes:
Where ballast tanks cannot be sounded reliably, or where the vessel is heeled or moving, the surveyor states this limitation in the report rather than presenting an unqualified figure.
Draft survey conditions vary by port. The Lower Mississippi has fresh river water, current and midstream operations; Houston and Galveston Bay have brackish water; Corpus Christi and Mobile have estuarine density. Each affects readings and density correction, and our reports record these conditions.
The Lower Mississippi is one of the world’s largest grain export corridors, with elevators between Baton Rouge and the river mouth, and midstream buoys used for grain, coal and other bulk transfers. River water density is close to fresh water, but current, wash from passing traffic and high-water seasons make draft reading demanding. Our surveyors read from the launch where needed and record river stage, current and wave conditions.
Houston and Galveston handle grain, petroleum coke, steel-related bulk and project cargo. Water in the Houston Ship Channel and Galveston Bay is brackish and can change density with tide and rainfall, so density is sampled at the time of each survey rather than assumed.
Corpus Christi handles grain through the public elevator, as well as aggregates and other dry bulk. Draft surveys are often combined with hold cleanliness inspections before grain loading.
These ports handle petroleum coke from nearby refineries along with other bulk cargoes. Petcoke loadings are usually measured by draft survey, and dust and trimming conditions are noted in the report.
Mobile is a major coal export port through the McDuffie Coal Terminal and also handles iron ore, steel raw materials and forest products. Coal loadings are commonly measured by draft survey, sometimes with intermediate checks before final trimming.
Amica Marine offers three draft survey scopes: an initial and final draft survey, a combined draft survey with loading or discharge attendance, and a desk review of another party’s draft survey for dispute support. Each scope is quoted in writing after confirming port, location and documents.
| Package | Deliverables | Timeline | Starting Investment |
|---|---|---|---|
| Initial and Final Draft Survey | Six-point draft readings, dock water density, ballast and deductible soundings, constant calculation, cargo quantity in metric tons, calculation sheets and written report. | Two attendances, before and after cargo operations; timing depends on the port, berth or anchorage and the ship’s location. | Quote on request – based on port, ship location and scope. |
| Draft Survey with Loading or Discharge Attendance | Initial and final draft surveys plus hold inspection, intermediate draft checks before trimming, operations log and stowage notes. | Covers the full loading or discharge; duration follows the terminal’s cargo rate. | Quote on request – based on port, ship location and scope. |
| Draft Survey Review and Dispute Support | Review of another surveyor’s calculation, vessel tables and conditions; written opinion on accuracy and likely sources of difference. | Desk review once documents are received; attendance added if the vessel is still in port. | Quote on request – based on port, ship location and scope. |
Attendance timing depends on the port and the ship’s location. Prices are not fixed: every survey is quoted on request, and the quotation is confirmed in writing before attendance. Launch hire for anchorage or midstream surveys and extended waiting time are listed separately.
Book a draft surveyor by calling 404-390-2132 or emailing info@amicamarine.com with the vessel, IMO number, berth or buoy, ETA, cargo and B/L quantity. We confirm scope and quotation, then attend for the initial and final surveys under written instruction.
A draft survey report includes observed draft readings, dock water density, tank sounding records, every correction applied, the calculation of displacement and constant, the cargo quantity in metric tons, notes on conditions affecting accuracy, and the surveyor’s signature and attendance times.
The report is written so a commercial manager can read the result on the first page and a technical reviewer can verify every step. It includes:
Please send the vessel name, IMO number, berth, buoy or anchorage, ETA, cargo type, B/L or nominated quantity, the name of the master or chief officer if available, and the party the report should be addressed to. A copy of the vessel’s hydrostatic tables and ballast tank calibration tables helps if the vessel will be at an anchorage.
An independent draft surveyor records the readings and corrections without a commercial interest in the result. Shippers, receivers, charterers and owners can then rely on one documented calculation instead of competing figures from the ship, the terminal and the counterparty.
Draft survey results depend on judgement: how drafts are read in swell, where density samples are drawn, whether ballast tanks are sounded or estimated. When the ship or one commercial party performs the survey alone, the other parties have little means of checking those judgements later.
An independent surveyor records them openly. If the figure is questioned months later in a shortage claim, the report shows exactly how it was obtained. For P&I clubs and cargo insurers, this documentation is often the deciding evidence.
Amica Marine acts for the party that appoints us, but we report quantities as measured. We do not adjust figures to match the bill of lading or the shore scale.
These answers address common questions from grain shippers, coal exporters, receivers, charterers and claims handlers before instructing a draft survey at a U.S. port. For a specific vessel, contact Amica Marine 24/7 at 404-390-2132 or info@amicamarine.com.
Under good conditions a draft survey is generally accurate to within about half a percent of cargo weight. Swell, current, unreliable tables or unsoundable tanks reduce accuracy, and our report states those limitations.
Yes. Cargo weight is the difference between initial and final displacement, so both surveys are required. Ideally the same surveyor performs both using the same tables and method.
Yes, but current and wash make readings harder. The surveyor reads drafts from a launch where needed and records river conditions, which may widen the margin of uncertainty noted in the report.
Density changes how deep a vessel floats. A small density error on a large bulk carrier can shift the cargo figure by many tons, so density is measured at the time of each survey, not assumed.
Yes. We review the calculation, tables and recorded conditions and give a written opinion on accuracy and likely sources of difference, which is often used in shortage or overage disputes.
Send the vessel name, port, ETA and survey type. We respond to survey inquiries 24/7 and coordinate surveyor attendance at major U.S. seaports on the Gulf, Atlantic and Pacific coasts.
