How to Manage Slip Reservations, Billing, and Maintenance for Marinas

A marina runs on three things: slip availability, fuel margin, and the sea wall holding up. The software job is to keep the first two transparent so you can focus on the third when it stops holding.

The daily reality looks like this. You have 180 wet slips split across annual contracts, month-to-months, and transients. You have a 96-stack dry storage barn with a forklift operator who needs 30 minutes of notice. You have a fuel dock pumping 89-octane gas and off-road diesel with prices that move weekly. You have an electric meter on slip 47 that the boat owner swears is broken. You have an EPA spill kit inspection due Friday. Hurricane Eulalia is forecasting a Cat 2 track into the bay in 11 days. And there is a 38-foot Sea Ray on slip 112 that has not paid since 2019, the owner is unreachable, and lien paperwork is sitting on your desk.

The right marina management software does five things: tracks slip inventory by length, depth, and amenity; bills annual, monthly, and transient guests on the right cycle; runs the fuel pump POS with per-gallon pricing and inventory tracking; ticketing for dock repairs and contractor coordination; and pushes emergency comms to every boat owner on file when a storm changes course. This guide walks through the operating playbook, step by step, the way a harbor master actually runs the day.

Slips are not interchangeable. A 28-foot center console fits a 30-foot finger pier. A 52-foot Hatteras with a 5-foot draft does not, even if the slip is technically 55 feet long, because the channel runs at 4.5 feet at low tide.

Build every slip as its own inventory record. Length overall (LOA), beam, depth at mean low water, side-tie vs covered vs floating, 30-amp vs 50-amp vs 100-amp service, water available yes or no, pump-out reachable yes or no, and per-foot rate. Tag each slip as annual-locked, monthly-available, or transient-bookable so the booking calendar does not double-sell a slip that has a permanent contract on it.

Electric is its own line. Some slips include power up to a cap (commonly 200 kWh per month) and meter the rest. Some are sub-metered from the start. Annual contracts often bundle electric, transient bookings almost never do — the transient pays cost-plus, billed at checkout from the meter reading. If your software cannot read a slip-level meter and bill the variance, you are losing two to four percent of revenue to under-billing.

Covered slips price 20 to 35 percent above open side-ties because the roof keeps gel-coat from chalking. Price each slip on its own merits, then publish the rate card so dockhands can quote without calling you.

These three customer types want three different billing experiences and they all want autopay.

Annual contracts. One invoice in January for the full year, or four quarterly invoices, with a 5 to 8 percent discount versus the monthly rate. Card-on-file with autopay is the default. Late on quarter two? The software should fire a 10-day notice, then a lien notice, then flag the slip for the harbor master before it goes to collections.

Monthly tenants. Recurring monthly invoice on the first, autopay 24 hours later, with electric overage from the prior month rolled in. These are the customers who are evaluating whether to upgrade to annual — the software should know they have been on month-to-month for 9 months and prompt the dockmaster to offer a conversion.

Transients. Booked through Dockwa, Snag-A-Slip, your own website, or by VHF radio at 4 p.m. on a Friday. Reservation in, deposit captured, slip assigned by length, electric meter read at arrival and departure, fuel charged at checkout, dockage billed at the per-foot rate times nights stayed. The transient ledger should close out at checkout with one swipe.

Late fees are a policy decision, not a software decision. Most marinas run a 5-day grace then a flat $50 late fee, or 1.5 percent per month, whichever is greater. Whatever you choose, the system applies it consistently — the boat that has been there since 2019 not paying is a story that started with one missed late fee being waived as a courtesy.

Fuel is the highest-volume revenue line at most marinas and the easiest one to lose money on through bad accounting.

The pump POS needs three things wired together. Per-gallon pricing that updates when your wholesale cost moves, ideally pulled from a daily rack price feed. A pump integration that reads gallons dispensed and writes the sale to the customer's slip account in real time. And tank inventory that decrements with every transaction so you know when you are 800 gallons from running dry on Saturday morning of Memorial Day weekend.

Fuel margins live and die on three numbers: wholesale cost per gallon delivered, retail price per gallon dispensed, and shrinkage between the two. Shrinkage of 0.5 to 1.5 percent is normal — temperature variance, evaporation, calibration drift. Shrinkage above 2 percent is theft, a leak, or a broken meter, and your software should flag the variance every reconciliation cycle.

Fuel sales tag to the slip if the boat is dockside, or to a walk-up account if it is a non-resident pulling up to the fuel dock. Either way, the sale flows to the same general ledger so end-of-month does not require a manual reconciliation between the pump computer and the office accounting software.

Floating docks rot. Pilings get hit. Cleats pull out. The water is corrosive and the sun is corrosive and the boats banging into the dock are the most corrosive of all.

Run a work order ticketing system the same way an HVAC company would. Slip 47 reports a loose cleat at 9:14 a.m. — ticket opened, photo attached, assigned to the dockmaster, parts ordered if needed, contractor scheduled if it is beyond in-house capability, customer notified when it is fixed. The ticket history per slip is the audit trail when an annual customer asks why their rate went up — you can show them $14,000 in dock work last year that justified the hike.

Contractor coordination is its own workflow. Diving services for hull cleaning and prop repairs. Electricians for shore-power pedestals. Welders for handrails and ladders. Each contractor is a vendor record with insurance certificate on file (expires? the system should warn you 30 days out), W-9 on file, and a dispatch flow that is the same as customer-facing tickets — request, schedule, complete, invoice.

Hurricane prep is the biggest predictable maintenance event of the year on the Atlantic and Gulf coasts. The 11-day forecast triggers a checklist: extra dock lines on every transient, dry-stack boats prioritized into the building, fuel tanks topped or drained per insurance policy, generators tested, spill kits staged, every slip holder gets the prep notification with their action items. The marinas that ride out Cat 2s with minimal damage are the ones that started the checklist on day 11, not day 2.

Every boat owner with a slip has three contact lanes that need to be live: email for billing and routine notices, SMS for urgent ops, and a phone number for genuine emergencies.

The routine flow handles fuel price changes, gate code rotations (rotate quarterly, more often if you have turnover in monthly tenants), seasonal hour changes for the ship store, and annual notice that the pump-out is closed for two weeks of dredging. None of this is dramatic. All of it is the difference between customers who renew and customers who leave one-star reviews about communication.

The urgent flow handles storm warnings, fuel dock closures, electrical outages affecting refrigeration on liveaboards, and security incidents. SMS to every active slip holder, segmented by transient vs monthly vs annual, sent in under two minutes when the situation requires it. The marinas that get this right are the ones whose customers find out about the closure from the marina, not from a Facebook post by another slip holder.

The emergency flow is rare and serious. A boat is sinking at slip 89. A liveaboard had a medical emergency. The fuel dock had a spill that needs Coast Guard notification. The software is not the answer here — a clear escalation tree is — but the software is the system of record that documents who was contacted, when, and what was done, which is what your insurance carrier and the EPA will want to see afterward.