Hull insurance covers physical damage to a ship, boat, or aircraft, paying to repair or replace the insured asset when it is harmed by collisions, storms, fires, groundings, and similar hazards. It protects the hull structure, onboard machinery, and the equipment needed to operate the vessel or aircraft. For owners whose livelihood or largest asset sits on water or in the air, this is usually the single biggest line of coverage they carry, and knowing what it includes, what it excludes, and how a claim moves forward can prevent expensive surprises after a loss.
What a Hull Policy Covers
A hull policy responds to physical loss or damage to the insured vessel or aircraft. The standard market form used in most marine hull policies lists covered perils including hazards of navigable waters, fire, explosion, violent theft by outsiders, jettison, piracy, contact with aircraft or dock equipment, and lightning or earthquake damage. Coverage also extends to damage caused by accidents during loading or discharging cargo, boiler bursting, shaft breakage, latent defects in machinery or hull, and negligence by the crew, pilots, or repair contractors.1Institute Time Clauses. Institute Time Clauses Hulls
Limits are tied to the asset’s appraised or agreed value, and insurers often require a professional appraisal or market assessment before binding a policy. Deductibles range from a modest flat dollar amount to a percentage of the insured value, depending on the vessel type, age, and the owner’s risk tolerance. A higher deductible lowers premium but increases what you pay out of pocket on smaller claims.
All-Risk Versus Named-Peril Coverage
Hull policies come in two shapes. An all-risk policy covers any accidental physical loss unless the contract specifically excludes it. A named-peril policy covers only the hazards written into the contract. The distinction is bigger than it looks. Under a named-peril form the owner has to prove the loss fits a listed peril. Under an all-risk form, the burden flips: the insurer has to prove an exclusion applies before it can deny.
All-risk costs more but closes gaps that named-peril leaves open. Owners of high-value commercial vessels and aircraft usually favor all-risk because unexpected causes of loss are common at sea and in the air. Recreational boat owners sometimes accept named-peril coverage to keep the premium down.
Provisions That Shape How a Claim Gets Paid
A few clauses inside a hull policy do most of the work in a loss. Reading them before an incident matters far more than reading them after.
Agreed Value
Most hull policies are written on an agreed-value basis, not actual cash value. When you buy the policy, you and the insurer settle on a figure for the vessel or aircraft. If a total loss occurs, the insurer pays that agreed amount minus the deductible, no matter what the asset might fetch on the open market at the time of loss. Depreciation is not deducted the way an auto insurer would deduct it on a car claim. That predictability is one of the main attractions of hull coverage, especially for aging vessels or aircraft whose market value swings.
Actual and Constructive Total Loss
Hull policies split total loss into two categories. An actual total loss means the asset is physically destroyed or damaged beyond any possibility of repair. A constructive total loss means repairs are technically possible but would cost more than the asset is worth. Under longstanding marine insurance law, a constructive total loss exists when the insured property is reasonably abandoned because preserving it from actual total loss would require expenditure exceeding its value.2LexisNexis. Marine Insurance Act 1906 C41 – Section 60 Constructive Total Loss Defined
The practical piece: when a constructive total loss is declared, the owner abandons the asset to the insurer and collects the agreed value. But the owner typically has to give formal notice of abandonment before the insurer is obligated to pay on that basis. Skip the notice and you can end up arguing over partial repair costs instead of collecting the full insured amount.
Navigation Limits
Every hull policy restricts coverage to specific geographic boundaries. A coastal fishing boat might be covered only within a defined radius of its home port. A cargo vessel might be approved for certain trade routes but excluded from high-risk waters. If the vessel operates outside those limits when damage occurs, the insurer can deny the claim. Courts have enforced these warranties strictly, holding that a breach releases the insurer from liability for any loss that occurs during the breach.
Some policies include a “held covered” clause that preserves coverage after a breach if the owner notifies the insurer immediately and agrees to any amended terms or additional premium. If your operations might take you outside your normal trading area, confirm the clause is in your policy before you leave.
Sue and Labor
Hull policies impose a duty on the owner after a covered loss: take reasonable steps to prevent further damage. If your vessel runs aground and is taking on water, you cannot wait passively for the adjuster while the loss worsens. In exchange, the insurer reimburses reasonable expenses for those protective measures in proportion to the insured interest. Keep receipts. Sue and labor expenses are recoverable, but only if you can document them.
Lay-Up Returns
When a vessel is taken out of active service for an extended period, the risk of loss drops. Most hull insurers offer a lay-up return, a partial refund of premium for the time the vessel sits idle. To qualify under typical terms, the vessel must be anchored or moored at a safe location with no cargo on board for at least 30 consecutive days, and the owner must notify the insurer within 30 days of commencing lay-up. A vessel that is detained, arrested, or physically prevented from trading does not count, because the owner did not voluntarily take it out of service.3Gard. Premiums and Calls – Rule 22 Laid-Up Returns
If lay-up runs beyond six months, the insurer may require an inspection before the vessel returns to service. The hull and machinery policy needs to stay in force during the lay-up period; letting it lapse can eliminate coverage for liabilities that would otherwise have been insured.3Gard. Premiums and Calls – Rule 22 Laid-Up Returns
Hull Coverage Versus P&I
Hull insurance and Protection & Indemnity (P&I) coverage are often confused, but they sit on opposite sides of a loss. Hull pays for damage to your own vessel. P&I covers your liability to third parties: crew injuries, cargo damage, pollution cleanup, and harm to other people’s property. A collision shows the split clearly. If your vessel hits another ship, hull pays to repair yours; P&I covers the damage you caused to the other ship, its cargo, and anyone injured.
Most commercial operators carry both, and many port authorities and flag states require P&I as a condition of registration. Neither policy substitutes for the other.
The Running Down Clause
One provision blurs the line. The running down clause, sometimes called the collision liability clause, is embedded in the hull policy and adds limited liability coverage for damage your vessel causes to another ship in a collision. Historically it covered three-quarters of the assessed collision liability, with the remaining quarter falling to the P&I club. Some modern policies extend to full collision liability, but the traditional three-quarters split is still common. The clause applies only to collisions with other vessels; striking a dock, bridge, or floating debris falls outside its scope.
How Aircraft Hull Coverage Differs
Aircraft hull coverage works on the same principle as marine hull insurance but splits the risk into two categories: ground risk and in-flight risk. Ground risk covers damage while the aircraft is parked, stored, hangared, or taxiing. In-flight risk covers damage during takeoff, flight, and landing. Ground-only coverage costs less, since parked aircraft are far less likely to suffer catastrophic damage than aircraft in operation.
Owners who store an aircraft and fly it only occasionally sometimes carry ground-risk-only coverage during idle periods and add in-flight coverage when the aircraft returns to active use. Premium factors include the aircraft’s value, its storage conditions (hangared or tied down outdoors), geographic location, and maintenance status. Like marine hull policies, aircraft hull is typically written on an agreed-value basis.
What a Hull Policy Excludes
Hull policies exclude categories of loss that either fall outside normal underwriting or reflect risks the owner should manage through maintenance and good judgment.
- Wear and tear. Gradual deterioration, corrosion, osmotic blistering, and mechanical breakdowns caused by age or deferred maintenance are not covered. Insurance is not a substitute for upkeep.
- Intentional damage. If an owner deliberately damages a vessel or aircraft to collect proceeds, the claim will be denied and the owner likely faces criminal fraud charges.
- Illegal activity. Losses that occur while the asset is being used for smuggling, unauthorized modifications, or other unlawful purposes are excluded.
- War, terrorism, and strikes. Standard hull policies exclude damage from war, civil war, revolution, insurrection, hostile acts by belligerent powers, capture, seizure, derelict weapons of war, strikes, labor disturbances, and terrorism. Owners operating in conflict zones can buy separate war risk insurance, but it carries a steep premium and the insurer usually retains the right to cancel on 48 hours’ notice.1Institute Time Clauses. Institute Time Clauses Hulls
- Nuclear events. Damage from nuclear weapons or radioactive contamination is excluded under virtually all standard hull forms.1Institute Time Clauses. Institute Time Clauses Hulls
Some excluded risks, particularly war and terrorism, can be picked up through specialized endorsements or standalone policies. The cost depends heavily on trading area and current geopolitical conditions.
What Drives the Premium
Hull premiums are generally calculated as a percentage of the insured value, but the percentage varies based on several factors:
- Vessel or aircraft type and value. Higher-value assets cost more in absolute terms but may attract lower percentage rates because they tend to be better maintained.
- Operating area. A vessel confined to coastal waters in the Gulf of Mexico pays less than one crossing the North Atlantic or transiting areas with piracy risk. Aircraft exposure to severe weather or challenging airfields raises premiums.
- Claims history. An owner with a clean record earns discounts, similar to a no-claims bonus in auto insurance. Recent losses push rates up or make coverage harder to find.
- Age and condition. Older vessels generally cost more to insure, and insurers may require periodic surveys by certified marine surveyors.
- Storage and mooring. A yacht in a secure marina or an aircraft in a locked hangar presents less risk than one tied to an open dock or an exposed tarmac.
- Deductible. A higher deductible lowers premium but increases your share of any loss.
Loss of Hire for Lost Income
Hull insurance pays for physical damage but not for the income a commercial vessel loses while sitting in a repair yard. Weeks or months out of service can mean hundreds of thousands of dollars in lost revenue. Loss of hire insurance fills that gap, paying a daily amount for each day the vessel cannot earn income due to damage that would be covered under the hull policy.4Nordic Plan. Chapter 16 – Loss of Hire Insurance
Loss of hire deductibles are measured in days rather than dollars. The owner absorbs a set number of waiting days before coverage kicks in. Coverage also responds when the vessel is stranded, physically blocked from leaving port, or undergoing salvage operations related to a covered casualty.4Nordic Plan. Chapter 16 – Loss of Hire Insurance It is purchased separately from the hull policy and is most common among owners of cargo ships, tankers, and offshore support vessels.
Filing a Claim
When damage occurs, most hull policies require the owner to report the incident within 24 to 72 hours. Missing that window can give the insurer grounds to reduce or deny the claim. The initial report should include the date, time, and location of the incident, a description of the damage, and supporting records such as maintenance logs, inspection reports, and crew statements.
After the report, the insurer sends a surveyor or adjuster to assess the damage. That evaluation determines whether repairs are feasible and what they will cost, or whether the loss qualifies as actual or constructive total. The owner needs to provide photographs, repair estimates, and witness statements. For marine losses, the insurer may appoint an average adjuster, a specialist in maritime claims who calculates the loss impartially and prepares the formal adjustment. Average adjusters advise the shipowner on options and likely financial outcomes, and their involvement tends to speed up settlement because both sides rely on the same independent analysis.
If salvage or wreck removal becomes necessary, additional reporting and documentation apply. Keep every receipt and record tied to the loss, including expenses you incur to protect the asset under the sue and labor clause. Organized documentation is the single biggest factor in getting a claim paid promptly.
When You and the Insurer Disagree
Disputes over claim amounts, coverage interpretation, or outright denials happen. Most policies build in a sequence for handling them.
Appraisal is usually the first step for valuation disputes. Each side picks an independent appraiser to assess the damage. If the two cannot agree, they appoint an umpire whose decision is binding. This is faster and cheaper than court, and it works when the disagreement is about how much a repair costs rather than whether the policy covers the loss at all.
Arbitration is written into many hull contracts as a mandatory step before either party can file a lawsuit. An arbitrator or panel hears evidence from both sides and issues a binding decision. Mediation is sometimes available as a less formal alternative; a neutral mediator helps the parties negotiate but cannot force an outcome. Litigation remains an option if all else fails, but maritime lawsuits can drag on for years and run up substantial legal fees. Read the dispute resolution clause carefully before a dispute escalates. It may require a specific sequence of steps, and skipping one can forfeit your right to the next.
Tax Treatment of a Payout
A hull payout for a total loss can trigger a taxable gain if the amount received exceeds your adjusted tax basis in the vessel or aircraft. The IRS treats the destruction of property as an involuntary conversion, and any gain realized is ordinarily taxable in the year you receive the proceeds.
Under Section 1033 of the Internal Revenue Code, you can elect to defer that gain by reinvesting the proceeds in replacement property similar in use to the property destroyed. The replacement must be purchased within two years after the close of the first tax year in which any part of the gain is realized. If the converted property was in a federally declared disaster area, the replacement period extends to four years.5Office of the Law Revision Counsel. 26 USC 1033 – Involuntary Conversions
Gain is recognized only to the extent the payout exceeds the cost of the replacement property. Spend the entire payout, or more, on a comparable replacement and the gain is fully deferred. Pocket part of the proceeds and buy something cheaper, and you owe tax on the difference. The election is made on your tax return for the year the gain is realized, and given the amounts involved in hull losses, working with a tax advisor before the filing deadline is worth the cost.
Federal Compliance Requirements
Regulation shapes both the coverage an owner must carry and the terms insurers include in their hull policies.
Certificate of Financial Responsibility
Under the Oil Pollution Act of 1990, any vessel over 300 gross tons using U.S. navigable waters must carry a Certificate of Financial Responsibility (COFR) issued by the U.S. Coast Guard’s National Pollution Funds Center. Tank vessels over 100 gross tons face the same requirement.6eCFR. 33 CFR Part 138 – Evidence of Financial Responsibility for Water Pollution The COFR shows the owner can cover pollution cleanup costs and damages.
A vessel without a valid COFR is barred from U.S. waters and can be denied port entry, detained, or seized and forfeited to the United States.6eCFR. 33 CFR Part 138 – Evidence of Financial Responsibility for Water Pollution Hull insurers serving the U.S. market typically ensure policies meet COFR requirements as part of underwriting, but the responsibility to verify compliance sits with the owner.
International Conventions
Commercial vessels operating internationally may need coverage that satisfies treaty obligations. The International Convention on Civil Liability for Oil Pollution Damage requires ships carrying more than 2,000 tons of oil in bulk as cargo to maintain insurance covering the owner’s total liability for a pollution incident. Government-owned commercial vessels are covered by the convention’s liability rules but are exempt from the insurance requirement if the flag state issues a certificate confirming coverage.7International Maritime Organization. International Convention on Civil Liability for Oil Pollution Damage (CLC)
Domestic rules matter too. Some jurisdictions require proof of insurance before a vessel or aircraft can be registered or operated commercially, and insurers must comply with consumer protection rules governing policy disclosures, claims handling timelines, and settlement practices. Confirm your hull policy meets all applicable regulatory minimums before putting the asset into service. Operating without adequate coverage can result in fines, loss of registration, or both.