How the project cost is built
A marina budget is the sum of a few large items, and each one is priced by the unit your quotes use. Docks are priced per square foot of dock or per foot of slip. Dredging is priced per cubic yard. Buildings, a seawall or breakwater, and the fuel dock and utilities are lump sums. Permits and design are a percentage of that construction cost, and a contingency is a percentage of construction plus permits and design. Land and working capital are added on top.
Every unit cost on this page is your own figure. The starting values are round illustrations so the page works on first load. They are not benchmarks or typical prices, so replace them with the quotes you have from contractors, engineers and your lender.
Worked example: a start-up marina with 20% equity
Take land at $1,000,000, 30,000 square feet of dock at $50 a square foot, 10,000 cubic yards of dredging at $20 a cubic yard, $500,000 of buildings, a $400,000 seawall and $250,000 for fuel and utilities. The docks come to $1,500,000.00 and the dredging to $200,000.00, so the construction cost is $2,850,000.00. Permits and design at 8% add $228,000.00 and a 10% contingency adds $307,800.00.
With $100,000 of working capital the total project cost is $4,485,800.00. Putting in 20% equity, which is $897,160.00, leaves a loan of $3,588,640.00, or 80.00% of the project. At 8.5% over 20 years the monthly payment is $31,143.05, which is $373,716.62 a year, and the interest over the term comes to $3,885,692.40.
To cover those payments 1.25 times, the marina needs $467,145.78 of net income a year. If slip rent is $7,500 a year and 40% of it goes on running costs, the rent income needed is $778,576.29, which means 104 slips.
Check against a published calculator
The calculator.net amortization calculator, given a loan of $3,588,640.00, 8.5% and 20 years, shows a monthly payment of $31,143.05 and total interest of $3,885,692.40. This page gives $31,143.05 and $3,885,692.40 for the same loan. The loan payment is the part of this page that other tools can check.
SBA 7(a) conditions for a start-up marina
This page checks the figures against SBA SOP 50 10 8.1, effective 1 October 2026, which governs 7(a) loans. SBA treats a business as a start-up if it has been operating, meaning generating revenue from its intended operations, for one year or less. For a start-up it expects an equity injection of at least 10% of total project costs, which the SOP defines as all costs required to become operational, regardless of the source of funds, except lines of credit and 504 loans. For start-ups, applications must include projections that show a debt service coverage of at least 1.15 within two years from loan funding or, for a construction project, within two years from the end of construction.
The maximum for one standard 7(a) loan is $5,000,000. On the default project the loan is $3,588,640.00, inside that limit. If the land costs $3,000,000 with 15% equity over 25 years, the total project cost is $6,485,800.00, the loan is $5,512,930.00 and the page flags it as above the limit. Cutting equity to 8% on the default project is below the 10% minimum, and the page says so while the loan grows to $4,126,936.00.
The SBA minimum coverage is easy to see in the income target. At the default 1.25 cover the net income needed is $467,145.78, while at the SBA's 1.15 it is $429,774.11. Choosing a cover of 1.1 for the default project gives a net income of $411,088.28 and a flag that it is below 1.15.
Loan term and the short-stay revenue rule
The SOP limits the term by what the loan pays for. Working capital loans and the financing of intangible assets must not exceed 10 years. Real estate loans, including construction, must not exceed 25 years, with extra time allowed for the construction period. A mixed-purpose loan can run up to 25 years if 51% or more of the proceeds are for real estate. The page marks a term of 10 years or less as within the working capital limit, 11 to 25 years as needing the real estate share, and longer than 25 years as over the limit.
The SOP treats hotels, motels, RV parks, marinas, campgrounds and similar businesses as eligible if more than 50% of the business's revenue for the prior year comes from transients who stay 30 days or less at a time. A start-up's projections must show more than 50% of revenue will come from such short stays. Enter your projected share and the page checks it: 60% passes, while exactly 50% does not because the rule says more than half. A 10-year term on the default project has a monthly payment of $44,494.00 against $28,896.70 over 25 years.
Docks by length, and what the estimate leaves out
If your dock quote is per foot of slip, switch the pricing. 3,200 feet at $475 a foot makes the docks $1,520,000.00, the total project cost $4,509,560.00, a monthly payment of $31,308.01 and 105 slips at the same rent.
This is a planning estimate, not an SBA eligibility or credit decision. It does not model the SBA guaranty fee, phased construction, interest during the build, a ramp-up in occupancy, other income such as fuel sales, storage or a restaurant, property taxes, or the 504 programme. A lender sets its own equity, coverage and pricing and may ask for more than the SOP minimum.
For a build with drawdowns, use the construction loan calculator .
To test debt service coverage on its own, use the DSCR loan calculator .
Use the right country page
This page is in dollars and uses US terms: slips, docks, square feet and cubic yards, with the interest rate as the nominal yearly rate. The country choices above the inputs open separate local pages. Choosing United Kingdom opens the marina loan start-up cost calculator for the UK, which uses pounds, berths, pontoons and metric units and makes no scheme claim. The inputs reset and amounts are not converted.
Inputs for the US marina loan start-up cost calculator
Land
The purchase price of the land or water lease with closing costs. Enter zero if you already own it.
Docks: pricing, quantity and cost per unit
Choose square feet of dock or feet of slip, then enter the quantity and your quoted cost for one unit.
Dredging volume and cost per cubic yard
The cubic yards to dredge and your quoted cost for each, including disposal.
Buildings, seawall or breakwater, fuel dock and utilities
Lump sums from your quotes. Enter zero for anything the project does not include.
Permits and design, and contingency
Permits and design are a percentage of construction cost. Contingency is a percentage of construction plus permits and design.
Working capital
Cash to run the marina until it earns.
Your equity, interest rate and loan term
Equity is a share of the total project cost. The loan is the rest, repaid monthly at a nominal yearly rate.
Debt service cover, rent per slip and running costs
Net income needed is the yearly payments times the cover. Rent after running costs sets the slips needed.
Revenue from short stays
The projected share of revenue from transients staying 30 days or less, used for the SBA marina check.
CALCULATOR QUESTIONS
US marina loan start-up cost calculator questions
How do you work out the start-up cost of a marina?
Add land, docks, dredging, buildings, a seawall and utilities, then permits and design and a contingency, and add working capital. In the worked example the total is $4,485,800.00.
How much equity does an SBA 7(a) start-up loan need?
SBA expects an equity injection of at least 10% of total project costs for a start-up, which is a business operating one year or less. A lender can ask for more.
What debt service coverage does SBA expect for a start-up?
Projections must show at least 1.15 within two years of funding. On the default project that is $429,774.11 of net income a year.
Can a marina get an SBA 7(a) loan?
SBA treats a marina as eligible if more than 50% of its revenue comes from transients staying 30 days or less. A start-up is tested on its projections.
How many slips do I need to cover the loan?
Divide the rent income needed by the rent per slip. In the worked example $778,576.29 at $7,500 a slip is 104 slips.
Are the unit costs typical prices?
No. They are round illustrations. Use your own quotes for docks, dredging and buildings.
What happens if I change country?
The United Kingdom option opens the separate UK page, in pounds, with no scheme checks. Your inputs are reset rather than converted.