14.3 Inland Marine and Nationwide Marine Definition

Key Takeaways

  • Inland marine covers mobile property, property in transit, bailee property, and instrumentalities of transportation/communication - the test is mobility/transit, not peril.
  • The Nationwide Marine Definition (NAIC, last major revision 1976) lists the classes eligible to be written as inland or ocean marine and is the regulatory boundary of the line.
  • Key forms include contractors equipment floater, builders risk, accounts receivable/valuable papers, bailee forms, and motor truck cargo.
  • Builders risk ends at the earliest of occupancy, expiration, or 90 days after construction completion.
  • Floaters may be written ACV (replacement cost minus depreciation) or replacement cost, subject to per-item sublimits and blanket limits.
Last updated: June 2026

What Inland Marine Actually Insures

Inland marine insurance covers property that moves, is in transit, or is held by a bailee, plus the instrumentalities of transportation and communication - bridges, tunnels, piers, pipelines, and radio/TV towers. Despite the word "marine," most inland marine risks never touch water. The line grew out of ocean marine cargo: early cargo policies ended when goods left the vessel, so insurers built an "inland" extension to follow shipments overland to the final destination.

Quick Answer: If property is mobile, in transit, or hard to fix to one address, it is usually an inland marine risk - not a commercial property risk.

The defining exam test is mobility or transit, not the type of peril. A $400,000 crane on a job site is inland marine (a contractors equipment floater); the same value in a boiler bolted to a building is commercial property.

The Nationwide Marine Definition (NMD)

Filed through the NAIC and last substantially revised in 1976, the Nationwide Marine Definition (NMD) lists the classes a company may write as inland or ocean marine. Underwriters must keep risks inside these classes; writing fixed-location, non-transit property as "inland marine" to dodge coinsurance and rate filings is a regulatory violation.

NMD ClassTypical Examples
Imports / ExportsGoods in foreign trade
Domestic shipmentsProperty in transit within the U.S.
Instrumentalities of transportation/communicationBridges, tunnels, piers, towers, pipelines
Personal property floatersJewelry, fine arts, cameras
Commercial property floatersContractors equipment, accounts receivable, EDP

The NMD is the regulatory boundary of the marine line - if a risk is not within an NMD class, it cannot be written as marine.

Major Inland Marine Forms You Must Know

Contractors Equipment Floater

Covers mobile equipment - dozers, cranes, compressors, tools - at job sites and in transit. Written open-peril; excludes wear, mechanical breakdown, and equipment licensed for road use (that belongs on commercial auto).

Builders Risk

Covers structures under construction, tracking rising project value (completed-value or reporting form). Coverage ends at the earliest of: occupancy, policy expiration, or 90 days after construction is complete.

Accounts Receivable & Valuable Papers

Reimburse the cost to reconstruct records and the sums the insured cannot collect because records were destroyed.

Bailee Forms

Cover customers' property in the insured's care, custody, or control (a furrier's customers' goods, a dry cleaner's bailee form). The bailee is not the owner but is legally responsible.

Motor Truck Cargo / Transit

A motor truck cargo policy covers a carrier's legal liability for others' freight; a shipper's/transit policy covers the owner's goods directly.

Worked ACV vs. Replacement Cost Example

Many inland marine floaters can be written Actual Cash Value (ACV) or Replacement Cost. ACV = replacement cost minus depreciation.

  • A contractor's loader originally cost $120,000, has a useful life of 10 years, and is 4 years old. Straight-line depreciation = 40%.
  • ACV = $120,000 x (1 - 0.40) = $72,000.
  • If the floater is written replacement cost and a comparable new loader costs $135,000, the insurer pays up to $135,000 (subject to the scheduled limit), with no depreciation deducted.

Trap: floaters often carry per-item sublimits and a blanket limit; the smaller of the applicable item limit and the remaining blanket controls the payout.

Floaters, the NMD Categories, and Filed vs. Non-Filed

Inland marine grew from ocean marine to cover property in transit, property of a mobile nature, and instrumentalities of transportation/communication (bridges, tunnels, towers). The Nationwide Marine Definition (NMD) lists the classes insurers may write as inland marine.

NMD categoryExamples
Imports/exportsGoods in international transit
Domestic shipmentsGoods moving within the country
Instrumentalities of transportation/communicationBridges, tunnels, pipelines, radio towers
Mobile/floating propertyContractors equipment, jewelry, fine art, cameras

Exam trap: A floater follows the covered property wherever it goes (often worldwide), which is why high-value movable items (jewelry, fine art, contractors equipment) are scheduled on inland marine floaters rather than left to a homeowners or commercial property sublimit.

Test Your Knowledge

The Nationwide Marine Definition primarily serves to:

A
B
C
D
Test Your Knowledge

A $400,000 mobile crane used at multiple construction sites is BEST insured under:

A
B
C
D

Filed vs. Non-Filed (Controlled) Classes

Inland marine splits into two regulatory buckets that the exam loves to contrast.

Filed ClassesNon-Filed (Controlled) Classes
ExamplesPersonal articles floater, EDP, accounts receivable, valuable papersContractors equipment, large transit, builders risk on big projects
Rates/formsMust be filed with the state and standardizedIndividually rated and negotiated by underwriters
WhyHigh-volume, homogeneous risksHeterogeneous commercial risks needing flexibility

Filed classes use bureau (ISO) rates and forms; non-filed classes give the underwriter freedom to tailor terms and price - which is precisely why marine is attractive for specialty risks but must stay inside the NMD.

Floaters, the Coverage Territory, and a Trap

Most inland marine coverage is written on a floater - a policy that follows the property wherever it goes within the coverage territory (usually the U.S., its territories, and Canada). A personal articles floater (PAF) schedules high-value items - jewelry, furs, fine arts, cameras, musical instruments - at agreed values with no deductible and broad worldwide open-peril coverage, filling the homeowners sublimit gaps.

Trap: the fine arts floater excludes loss from breakage of fragile articles unless caused by a specified peril (fire, theft, collision), and the musical instrument floater excludes use for pay unless endorsed. Scheduling at agreed value also means the stated amount is paid without depreciation - unlike unscheduled ACV coverage.