Underwrite a Marathon, FL DSCR Without the Islamorada Blend

Aug 19

11 min read

Updated: Aug 27

Seven Mile Bridge from the Keys, Marathon

Marathon sits roughly at the midpoint of the Florida Keys, incorporated as its own city with its own vacation rental license and its own published short-term rental year: $56,513 across 1,067 listings, ADR $534, occupancy 39.3 percent, in the vintage running August 2025 through July 2026. That figure belongs to Marathon specifically. It does not belong to Islamorada, which printed $46,255 on 368 listings in the same window, or to Key West, Duck Key, or Key Colony Beach, each of which is its own incorporated file with its own licensing desk.

This is not legal advice and not underwriting advice. It describes what the published data says about Marathon and flags the two most common ways a Keys DSCR file gets contaminated before it reaches a lender: blending in a neighboring island's revenue, and treating the city's vacation rental license as if it transfers automatically with the sale. Neither substitutes for a lender's own ratio calculation, an appraisal, or a direct call to Marathon's Fire Rescue and Code Compliance offices to confirm the parcel's actual status.

The Year That Belongs to This City

Marathon's own extract shows $56,513 in typical annual revenue across 1,067 listings, with ADR of $534 and occupancy of 39.3 percent, producing RevPAR of $220. Average stay length runs 7.3 nights, well above a typical weekend-market figure, and lead time between booking and arrival averages 104 days — guests are planning Keys trips months in advance, not booking on impulse.

The peak months are March, February, and April, and September is the softest month in the sample, with the low stretch continuing into October and November. Two hundred seventy-three listings, 25.6 percent of the sample, are configured to accept stays of 30 nights or longer, which is a meaningful share worth noting but is a calendar setting, not proof that those listings are actually booked through the fall shoulder season.

These numbers describe Marathon's own 1,067-listing sample in this specific vintage. A DSCR file for a Marathon parcel should carry exactly these figures, and no figure that belongs to a different incorporated city nearby, however close it sits on the map.

The 104-day average lead time is worth underwriting attention on its own. A market where guests book more than three months ahead behaves differently than a last-minute weekend market when it comes to cancellation risk and off-season cash flow planning — a canceled booking made in June for a March stay gives an operator far more runway to re-list than a canceled same-week booking would. That runway doesn't change the revenue number, but it changes how a lender should think about volatility around it.

Why Islamorada's Number Stays on Its Own Line

Islamorada printed $46,255 on a sample of 368 listings in the same vintage — a real, separate figure, not a smaller version of Marathon's number. The two cities have different sample sizes, different licensing regimes, and different local governments, and averaging their revenue to produce a rounder 'Keys' figure describes a rent roll that doesn't correspond to any actual parcel.

Two more nearby markets deserve the same treatment: Duck Key functions as a neighbor reference table in this dataset rather than a town with its own confirmed published year, and Key Colony Beach is a separate incorporated city sitting immediately next to Marathon with its own municipal government. Neither should be flattened onto Marathon's $56,513, and neither should have Marathon's license or ordinance status applied to it. Key West, further down the chain, is a different island entirely and has no bearing on a Marathon file.

The practical test for a lender or a borrower assembling the packet is simple: if the parcel sits inside the City of Marathon's boundaries, use $56,513. If it sits in Islamorada, the correct figure is $46,255. If it sits somewhere else in the Keys, open the extract for that specific municipality rather than reaching for whichever number is closest at hand.

The License Doesn't Transfer at Closing

A City of Marathon vacation rental license is issued annually and does not transfer with the sale of the property. A new owner has to apply fresh after closing — this is a licensing fact, not a revenue fact, but it changes the underwriting timeline because a lender assuming an existing license carries over to a new borrower is assuming something the city's own process doesn't allow.

The application stack the city names includes a Florida DBPR registration under FS 509 (the statewide hotel and restaurant licensing statute that covers vacation rentals), a Florida tax certificate, a Monroe County business tax receipt, a Monroe County Tourist Development Tax account, and a fire inspection. Fire inspection has to happen before the license issues, which means a DSCR file assuming rental-ready status without a completed fire inspection is underwriting a use the city hasn't actually approved yet.

Two related but different fee structures exist nearby and should not be substituted into a City-of-Marathon file: an Unincorporated Monroe County Special Vacation Rental permit runs $490, and an Islamorada Village license runs $1,325. Both are real fees, at real desks, for different jurisdictions — neither is the Marathon city fee, and pasting either number into a Marathon packet misstates what the borrower will actually owe.

A buyer relying on a seller's representation that 'the license comes with the house' should treat that claim as a marketing statement, not a fact confirmed by the city. The safest posture in a purchase contract is to structure the closing timeline around confirming license approval before funds change hands, or at minimum to budget the license application fee and processing time into the deal separately from the purchase price, rather than assuming day-one rental readiness.

Reading Plus 1.3 Percent Against Plus 19.1 Percent Supply

Marathon's year-over-year change is plus 1.3 percent, alongside supply growth of plus 19.1 percent — modest revenue growth in a market absorbing a meaningfully larger number of competing listings. Both figures belong on the same line in a lender narrative; showing the growth figure alone without the supply context overstates how much stronger any individual listing's position actually got.

Professional management covers 35.3 percent of the sample, with Vacation Rentals of the Fla Keys the largest single manager at 117 listings, followed by Coco Plum at 62 and Leslie at 48. Superhost status covers 48.0 percent of the sample. Three-bedroom units are the dominant configuration at 27.7 percent, and listings sized for eight or more guests make up 49.5 percent — Marathon skews toward larger group properties more than a typical coastal market.

None of this changes the core revenue figure. It rounds out the operating context: a market with meaningful professional management presence, growing supply, and modest but real revenue growth, all specific to Marathon and not transferable to a neighboring city's file.

The size mix matters for a buyer comparing an available parcel against the sample average. A two-bedroom cottage bought at a price calibrated against a market average built around 27.7 percent three-bedroom and 49.5 percent eight-plus-guest capacity is likely to underperform that average on ADR alone, independent of anything the operator does right. Matching the subject property's actual bedroom and capacity count against the sample composition, not just the top-line revenue figure, is part of an honest read of this data.

Turtle Hospital and the Seven Mile Bridge Aren't Debt Service

The Turtle Hospital, Seven Mile Bridge, Sombrero Beach, Crane Point, and Overseas Highway itself are the landmarks that put Marathon on a map for visitors — and none of them convert directly into occupancy figures for any specific listing. A DSCR narrative that leans on bridge traffic or hospital visitor counts to imply stronger demand than the extract shows is presenting tourism volume as if it were a booking calendar.

Miami functions as Marathon's primary origin market, and roughly 93 percent of guests are domestic travelers rather than international visitors. Neither of those facts should be used to inflate the typical year figure — they describe where guests come from, not how many nights they book.

The extract already names March as the peak month, with February and April rounding out peak-3, and September as the hole with October and November trailing low. Visitor landmark traffic doesn't move those months around; it's a marketing narrative that belongs after the revenue figure is established, not a substitute for it.

A Quarter of Listings Set to 30-Plus Nights Isn't a Filled September

Twenty-five and six-tenths percent of Marathon's sample — 273 of 1,067 listings — accept stays of 30 nights or longer. That's a meaningful chunk of the market testing extended stays, but it's a calendar configuration, not confirmation that September, the softest month in the data, is actually booked through those listings.

The dominant minimum-stay pattern across the sample is seven to twenty-nine nights, used by 61.7 percent of listings — Marathon already runs on a longer average booking pattern than a typical weekend-driven market, with average stay length at 7.3 nights overall. That existing long-stay culture makes the 30-plus setting more plausible as an actual demand response than it would be in a market built entirely around two-night minimums, but the extract still doesn't show it converting into filled fall occupancy.

A vacancy assumption in the DSCR ratio should still name September, October, and November as the soft stretch specifically, rather than assuming the 25.6 percent long-stay share smooths out the seasonal dip. If actual booking data later shows those months filling in, that's a stronger number than the setting count alone provides.

Monroe County's Tourist Development Tax still applies at 5 percent regardless of stay length, but the tax treatment of a 30-plus-night booking can differ from a standard short stay depending on how the county classifies the reservation. That's a bookkeeping question for the borrower's accountant, not a revenue question for the DSCR file — it doesn't change the $56,513 typical year, and it shouldn't be confused with an occupancy argument.

What a Marathon Lender Packet Should Carry

A complete file names the address and confirms whether the parcel sits inside the City of Marathon or in unincorporated Monroe County, since that distinction determines which license fee and which ordinance apply. It carries $56,513 as the typical year on 1,067 listings, the August 2025 through July 2026 vintage, plus 1.3 percent year-over-year alongside plus 19.1 percent supply growth, September named as the hole with March, February, and April as the peak three, and the license's non-transferable status stated plainly rather than assumed away.

It carries Fire Rescue's number, (305) 743-5266 at Station 14, 8900 Overseas Highway, and Code Compliance at (305) 743-0033, since both offices are part of the licensing path a new owner has to complete. It carries the Monroe County Tourist Development Tax rate of 5 percent as a line item, separate from the revenue figure.

It does not carry Islamorada's $46,255, a Key West or Duck Key figure, the unincorporated Monroe fee of $490, or the Islamorada Village fee of $1,325 presented as if any of them applied to this parcel. The ratio math — PITI, taxes, insurance, and a vacancy haircut that actually names the September-through-November stretch — is the lender's calculation to run once this material is in hand, not something this page invents on the borrower's behalf.

If an underwriter pushes for a fuller history than one vintage's extract, the answer is a trailing-twelve-month statement from the current owner for that specific address, not a wider search radius. A real T12 tied to the actual parcel will always carry more weight than a market-level figure, blended or not, and asking for it directly is a stronger move than trying to make the extract say more than it does.

Frequently Asked Questions

What revenue figure should a DSCR lender use for a Marathon short-term rental?

Use Marathon's own published typical year of $56,513 across 1,067 listings, vintage August 2025 through July 2026, with ADR of $534 and occupancy of 39.3 percent. If the subject property has its own trailing-twelve-month actuals, those outrank the market extract. What shouldn't appear in the file is an Islamorada, Key West, or Duck Key figure presented as if it belonged to a Marathon address.

Can I blend in Islamorada's numbers since it's a nearby Keys market?

No. Islamorada printed $46,255 on a separate sample of 368 listings, with its own licensing regime and its own municipal government. Averaging Marathon and Islamorada produces a number that doesn't correspond to either city's actual market. Keep each figure on its own labeled line if you reference both in the same document.

Does the City of Marathon vacation rental license transfer when I buy the property?

No. The license is issued annually and does not transfer at sale — a new owner has to apply fresh through the city's process, which includes a Florida DBPR registration under FS 509, a Monroe County Tourist Development Tax account, and a fire inspection. This is not legal advice; confirm the current application requirements directly with Marathon's Code Compliance office before assuming timeline or cost.

How does Marathon's year-over-year trend look for underwriting purposes?

Marathon printed plus 1.3 percent year-over-year alongside plus 19.1 percent supply growth in the same vintage. That's modest revenue growth in a market where competing listings grew substantially faster, which is worth stating plainly in a lending narrative rather than presenting the growth figure alone.

Do Turtle Hospital or Seven Mile Bridge visitor numbers support a stronger DSCR case?

No. Those landmarks explain why Marathon draws visitors, but visitor counts at a hospital or bridge don't convert into occupancy at any specific listing. The published occupancy figure — 39.3 percent — already accounts for actual booking behavior across the sample; tourism attraction volume is a separate, unrelated metric.

What's the difference between the City of Marathon license and the unincorporated Monroe County permit?

They're different desks with different fees. The City of Marathon's annual vacation rental license applies inside city limits. An Unincorporated Monroe County Special Vacation Rental permit, which runs $490, applies outside the city. A third option, Islamorada Village's own license at $1,325, applies only inside that separate municipality. Confirm which jurisdiction actually governs your parcel before assuming a fee.

Is September a good month to underwrite as filled for a Marathon rental?

No. September is the softest revenue month in Marathon's published data, with October and November trailing close behind. A quarter of listings are configured to accept 30-plus-night stays, but that's a calendar setting, not confirmed fall occupancy. A vacancy haircut in the DSCR ratio should name that stretch specifically rather than applying a flat seasonal discount.

What professional management share should I expect in Marathon?

Professional management covers 35.3 percent of the sample, with Vacation Rentals of the Fla Keys the largest single manager at 117 listings. That leaves close to two-thirds of the market self-managed, which is useful context if you're comparing operating cost assumptions against a fully professionalized market.

Who do I call to confirm fire inspection and code compliance status before closing?

Fire Rescue's vacation-rental inspection path runs through Station 14 at 8900 Overseas Highway, reachable at (305) 743-5266. Code Compliance answers at (305) 743-0033. Both offices are part of the license application stack a new owner completes after closing, since the license itself doesn't transfer with the sale.

Can I use Key West or Duck Key figures if my Marathon comp set feels thin?

No. Key West is a separate island with its own market data, and Duck Key functions only as a neighbor reference table in this dataset rather than a town with a confirmed published year of its own. The only figure this file should cite for a Marathon parcel is Marathon's own $56,513 on 1,067 listings — if the address isn't actually in Marathon, open the extract for whichever city it's really in.

Work with Crest & Cove Creative

Marathon's own published year is $56,513 on 1,067 listings, but the license doesn't transfer to a new owner at closing. A listing that blends in Islamorada's numbers is describing a parcel that doesn't exist.

We help independent Keys hosts keep their listing copy and license status tied to Marathon specifically, not a rounded regional average from Islamorada. Send us your listing at crestcove.co or call (256) 998-7502.

Reach out at crestcove.co or (256) 998-7502.