Aviation & marine services

Books and taxes for mobile marine mechanics.

Dock-side diagnostics, a rolling van full of parts, marina gate fees, and a stranded-boater call on a Saturday morning. Your own bookkeeper stays on it all year, an accountant checks every transaction, and you get one number a month.

Book a call What we handle
  • From $197 a month
  • An accountant on every transaction
  • Cancel whenever
MayExample month
$7,500
what you made

May came in at $7,500. The new impeller and belt stock you loaded into the van went in as inventory, not a one-time supply cost.

  • Dock call, won't-start diagnosisService calls
  • Weekend emergency callEmergency dock calls
  • Fisheries Supply van stock orderParts and van inventory
  • Marina gate access feeMarina and dock access
  • Fuel, service vanVehicle and fuel
Money in$24,600
Money out$17,100
Set aside for taxes$1,900
An example month. Yours will have your numbers.

Why your books are different

A mobile marine mechanic's books go wrong in the same few places.

A generalist sees a van full of parts and a pile of gas receipts. Your business is dock calls billed by the visit, travel time across three marinas a day, and a rolling inventory that never sits still. When the books do not know that, you cannot tell which calls actually pay.

  1. 1

    Travel time disappears into the service fee

    Driving between three marinas in a day is real time that is not turning a wrench, and if a flat service fee swallows the drive, you cannot tell whether a spread-out route is actually worth running.

    What we doKeeps travel and drive time visible against the service fee charged, so a route that eats the day shows up as what it is.
  2. 2

    Van stock looks like a one-time supply run

    Impellers, belts, fuel filters, and spark plugs bought to keep the van stocked get used across weeks of calls, and if the whole order lands as an expense the day you buy it, one good stock-up trip makes the month look thin.

    What we doKeeps van inventory in its own steady line so a restock does not read as an unusually expensive week.
  3. 3

    Marina access fees get lost in fuel receipts

    Some marinas charge a gate or dock access fee just to bring your van and tools onto the property, separate from anything you spend on gas, and mixed together it hides what it costs to work at each marina.

    What we doKeeps marina and dock access fees in their own line, so you can see what each marina actually costs you to service.
  4. 4

    A weekend emergency call gets billed like a Tuesday visit

    A Saturday morning call for a boat that will not start before a trip carries a premium, and if it is logged the same as a routine weekday visit, you lose track of what the rush work is actually worth.

    What we doKeeps emergency and after-hours calls in their own line, so the premium you charge for rush work is visible every month.

Your categories

The categories Gus keeps for a mobile marine mechanic.

Set up once for how you get paid and what you spend. You never pick a category. He does, and an accountant checks it.

Money in

  • Service callsRoutine dock-side diagnostics and repairs, billed by the visit.
  • Emergency dock callsWeekend and after-hours calls, kept apart to show the rush premium.
  • Winterizing and commissioningSeasonal lay-up and spring start-up work billed by the boat.
  • Standing marina contractsMarinas or boat clubs that pay for on-call mechanic coverage.

Money out

  • Parts and van inventoryImpellers, belts, filters, and spark plugs stocked for the road.
  • Marina and dock accessGate fees and access charges at the marinas you service.
  • Vehicle and fuelThe van, its fuel, and its maintenance.
  • Tools and diagnostic equipmentPortable diagnostic gear that travels with the van.
  • InsuranceLiability coverage for working on boats you do not own.

What we watch for you

  • Cost per marina

    Access fees and drive time against what each marina's calls actually bring in.

  • Emergency call share

    What portion of the month's calls were weekend or after-hours, the number behind whether the rush fee actually covers being on call.

  • Van inventory turn

    How fast stocked parts get used, so restocks match what the route actually needs.

  • The set-aside

    What you will owe, tracked every month, so April is a number you already knew.

Ask Gus

Things mobile marine mechanics ask Gus.

Text him like you would text anybody. He answers in plain English, and when a question is above his pay grade, an accountant looks and gets back to you.

I drove to three marinas today but only billed two service calls. Does that show up anywhere?

I keep travel time visible against what you billed, so a spread-out day like that is something you can actually see, not just feel.

One of the marinas started charging a gate fee just to bring the van in. Where does that go?

Its own line, marina and dock access. Now you can see exactly what it costs to keep working that dock.

I stocked the van with a big parts order. Does that wreck this month's numbers?

No. I keep van inventory in one steady line, so a restock reads as what it is, not a sudden bad week.

The tax side

The tax side of a mobile marine mechanic business.

Most of what goes wrong here is vehicle costs and timing. Van inventory, mileage, and a rush call that should be tracked separately from a routine one.

What your return has to get right

Your accountant signs it, so it gets done right the first time.

  • Vehicle and mileage deductionBusiness driving between marinas can be deducted at 72.5 cents a mile through June 2026 and 76 cents from July, or through actual van expenses, whichever the accountant finds fits your year.
  • Diagnostic equipmentPortable diagnostic tools and equipment can often be expensed the year you buy them under Section 179, up to $2,560,000.
  • Contractor 1099sAny outside help you paid $2,000 or more in 2026 who is not on payroll gets a 1099-NEC by January 31. Gus keeps the list all year.
  • The pass-through deductionMost owner-operators can take up to 20 percent of business profit off their taxable income. It comes out right when van inventory, travel, and calls are booked right all year.

Deductions mobile marine mechanics miss

Your bookkeeper knows what to look for in your statements. You never have to.

  • Van fuel and maintenance
  • Impellers, belts, and filters stocked in the van
  • Marina and dock access fees
  • Portable diagnostic equipment
  • Tool insurance
  • Liability insurance
  • Uniforms and safety gear
  • Phone and dispatch software
  • Cellular signal booster for remote docks
  • Manufacturer training and certifications

General information about 2026 federal rules, not advice for your business. Your accountant looks at your actual numbers before anything gets filed.

All year, not just April

A mobile marine mechanic's year, kept every month.

Boats break whenever an owner needs them to run. Your taxes come on a schedule. Your team keeps you ahead of both. Every month in between, your bookkeeper closes the books and speaks up the moment something looks off.

  1. January

    Plan the year

    Last year's return gets started, the 1099 list is ready, and you get a monthly set-aside so April is already handled.

  2. April

    Filed. Done.

    Your return is filed and signed. No surprise bill, because the set-aside has been running since January, right before commissioning season picks up.

  3. July

    Halfway check

    Where you stand, what you will owe, and whether the summer rush of dock calls changed the number more than usual.

  4. October

    Before winterizing season

    Owners book winterizing before the first freeze. Gus looks at van equipment worth buying and anything worth doing before December.

What you get

Starts at$197a month

What you pay depends on what your business needs, and it does not move after that, busy season or slow. No hourly bills, no surprise invoices, no setup fee.

Book a call
  • Monthly bookkeeping

    Every transaction sorted into categories set up for mobile marine mechanics. You never categorize a thing.

  • An accountant checks every transaction

    Real review, every month, before your books close. Not a spot check.

  • Your business tax return, filed

    Prepared, reviewed, and signed by that same accountant every year.

  • The monthly number

    What you made, what you spent, what to set aside for taxes.

  • Your own bookkeeper

    A real person assigned to your business, in the app whenever you need them. No hold music.

  • On your books all year

    Every month, not just in April. Your team speaks up whenever something is worth your attention.

  • Cancel any time

    No contract. No cancellation call. Your books are yours.

Straight answers

Questions mobile marine mechanics ask first.

Can Gus track which marinas are worth the drive?

Yes. He keeps access fees and travel visible against what each marina's calls bring in, so you can see which routes actually pay for the time.

Do I need to change how I invoice from the dock?

Not at all. Write up the call the way you always have. Gus reads the deposit when it lands and only texts you if a payment does not obviously match a call you ran.

My parts inventory rides in the van, not a shop shelf. Does that change anything?

It changes where it sits, not how it is tracked. Gus keeps van stock in its own line so a restock trip does not look like a bad week.

Do weekend emergency calls get taxed differently?

No, income is income. But Gus keeps emergency calls in their own line so you can see the premium you charge for rush work, which helps with pricing, not taxes.

I have a stack of statements from a slow few months I never sent in. Is that a problem?

Not for Gus. Send whatever you have sitting around, in whatever order you have it. He works through the pile and the accountant checks it, so most mechanics know where they stand within a week.

Is a real accountant checking my books?

Yes. You get your own bookkeeper, Gus does the first pass on every transaction, and an accountant checks every one before your month closes. That same accountant prepares, signs, and files your business return. Goatkeeper is not a CPA firm, and we never pretend a person looked when they did not.

What does it cost, and can I cancel?

It starts at $197 a month, depending on what your business needs. No setup fee, no hourly bills, no contract. Cancel any time from the app, and your books go with you.

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Book a call

Pick a time. That's the whole signup.

Fifteen minutes with a real person on our team. They look at where your books are, tell you straight what it takes to get caught up, and get you set up on the spot if it fits.

  • $197 a month to start
  • An accountant on every transaction
  • Cancel whenever