Real Estate, Specialty & Niche

How to Underwrite a Marina: Slips, Storage and Fuel

Underwrite a marina by separating stable storage income (wet slips, dry stack, winter storage) from volatile ancillary income (fuel, service, ship store), then sizing debt mainly on the storage NOI. The metrics that matter most are slip occupancy and rate per linear foot, storage share of NOI, and DSCR after a realistic dredging and dock capex reserve.

What makes marina underwriting different

A marina is part real estate, part operating business. The durable value sits in waterfront slips and dry stack racks, which are scarce because new marina permits are hard to obtain in most coastal and lake markets. The risk sits in the ancillary lines: fuel sales swing with boating seasons and fuel prices, service departments depend on a few skilled mechanics, and ship stores carry inventory. Physical risk is unusually concentrated. Docks, bulkheads, lifts and forklifts wear out on fixed cycles, channels silt and need dredging, and a single hurricane or flood can take the property offline for a season. Many marinas also sit partly on leased submerged land, which can cap the life of the collateral.

Lenders tend to underwrite a marina like specialty commercial real estate with operating risk layered on top. They focus on contracted annual slip and storage income, haircut fuel and service revenue, stress occupancy for a weak season, and require a meaningful capex reserve plus insurance that covers named storms. Equity buyers look for upside the lender will not pay for: below-market slip rates, unbuilt dry stack capacity, a fuel dock that is underpriced, or a service department that can be expanded. Equity also prices scarcity, so the exit thesis often depends on the replacement-cost argument rather than current yield, which a lender will not credit.

Key metrics

Slip and rack occupancy

Storage is the recurring core of marina income, so occupancy by slip size shows how much of NOI is truly stable. Large slips and small slips often have very different demand.

Lenders commonly want to see stabilized annual occupancy in the high 80s percent or better, broken out by slip length.

Rate per linear foot

Slip pricing is quoted per foot of boat length, so comparing the in-place rate to nearby marinas reveals mark-to-market upside or overpricing risk.

Storage share of NOI

The higher the share of NOI from annual slip and dry stack contracts, the less the cash flow depends on fuel prices and weather.

Underwriters often prefer storage to drive the majority of NOI and haircut fuel and service contributions.

DSCR

Seasonality means monthly cash flow is lumpy, so coverage must hold on an annual basis after reserves and in a weak season.

Lenders typically look for 1.30x to 1.40x or higher given the operating component.

Capex reserve per slip

Docks, pilings, bulkheads and dredging are recurring and expensive. Ignoring them overstates NOI.

Fuel gross margin per gallon

Fuel volume can look large but margin per gallon determines what it actually contributes and how sensitive it is to price swings.

Remaining submerged land lease term

If the state or a landlord owns the bottomland, the lease term limits loan maturity and exit value.

Lenders commonly require the lease to run well beyond the loan maturity, often by 10 years or more.

How to underwrite it, step by step

Build a rent roll of every wet slip, dry rack and storage space showing boat length, contract type, term and rate per foot.
Split trailing twelve month revenue into storage, fuel, service, ship store, launch fees and other, and margin each line separately.
Benchmark slip rates and waitlists against competing marinas within the same boating market.
Commission a marine engineering inspection of docks, pilings, bulkheads, lifts and forklifts, and get a dredging history and depth survey.
Confirm riparian rights, submerged land lease terms, and all environmental and fuel dock permits.
Model NOI with a full capex reserve and stress a lost season from a named storm or low water.
Price storm, flood and pollution insurance and confirm business interruption coverage before sizing debt.
Size the loan on storage-weighted NOI and set covenants around insurance, reserves and the land lease.

Due diligence checklist

Slip and dry stack rent roll with boat lengths and rates per foot
Seasonal slip and storage contracts and waitlist
Monthly P&L by department for three years
Fuel purchase and sales records with gallons and margins
Submerged land or bottomland lease
Riparian rights and title survey including water boundaries
Marine engineering and dock condition report
Dredging permits, history and bathymetric survey
Fuel dock environmental permits and spill prevention plan
Phase I ESA covering fuel tanks and boatyard operations
Insurance policies and storm loss history
Forklift, travel lift and equipment schedule

Key risks and mitigants

Hurricane, flood or ice damage closes the marina for a season.

Require named storm and flood coverage plus business interruption insurance, and stress DSCR with a lost peak season.

Channel silting reduces navigable depth and makes large slips unusable.

Obtain a depth survey and dredging permit history, and reserve for the next dredging cycle in the model.

Submerged land lease expires or is not renewed.

Match loan maturity well inside the lease term and confirm renewal rights and assignment consent.

Fuel dock contamination or spill liability.

Review tank age, leak detection and spill plans, order a Phase I ESA, and consider environmental insurance.

Dock and bulkhead deferred maintenance larger than disclosed.

Use a marine engineer, fund an upfront repair escrow and set an ongoing capex reserve.

Service department depends on one or two mechanics.

Haircut service income and review retention arrangements for key technicians.

Typical financing and deal structure

Marinas are usually financed with bank or credit union commercial mortgages, often at moderate leverage because of the operating component, and SBA 7(a) or 504 loans are common for owner-operators buying a single marina. SBA 504 works well when the real estate and dry stack buildings make up most of the value. Larger multi-marina platforms use private credit or institutional real estate debt secured by a portfolio. Seller financing appears frequently in family-owned marina sales to bridge valuation gaps. Typical covenants include minimum DSCR, a funded capex or dredging reserve, insurance requirements specific to named storms and pollution, and restrictions tied to the submerged land lease. Equity is often underwritten on adding dry stack capacity.

Red flags

Submerged land lease with fewer remaining years than the proposed loan term or no renewal option.
No dredging permit or depth survey and large slips that already show reduced access at low tide.
Fuel and service revenue presented as the main source of NOI with storage income declining.
Undisclosed storm damage or open insurance claims on docks and bulkheads.
Underground fuel tanks past their expected life without leak detection records.

Frequently asked questions

How are marinas valued?

Marinas are usually valued on capitalized NOI, with storage income weighted more heavily than fuel and service. Appraisers also consider replacement cost, since new marinas are hard to permit, and the remaining term of any submerged land lease. Buyers often add value for unused dry stack capacity or slip rates below market, but lenders generally size debt only on in-place stabilized income after a capex reserve.

Can you use an SBA loan to buy a marina?

Yes. Owner-operated marinas are commonly financed with SBA 7(a) or SBA 504 loans, since the buyer runs the business and the property together. The SBA program requires the business to meet size and eligibility rules, and lenders still look at storage occupancy, capex needs, insurance and the bottomland lease before approving. Passive marina real estate investments generally do not qualify.

What is the biggest risk in marina underwriting?

Physical risk is usually the largest. Storms, flooding, ice and silting can damage docks or make slips unusable, and repair costs are high. Underwriters address this with marine engineering inspections, dredging and capex reserves, named storm and business interruption insurance, and a stress case that assumes a lost peak season. Bottomland lease term is a close second.

What income at a marina is most reliable?

Annual wet slip and dry stack storage contracts are the most reliable because boaters prepay for a season or year and tend to renew. Winter storage is also fairly predictable. Fuel, service, boat rentals and ship store sales vary with weather, fuel prices and consumer spending, so lenders typically haircut them when sizing debt.

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Educational content, not investment, credit, legal or tax advice. Benchmarks are common practitioner rules of thumb and vary by lender, market and cycle.