WatchLog

A Real Logbook for Mechanical Watch Collectors

Mechanical watch collecting has a paperwork problem. Every serious collector eventually ends up with a smudged notebook in a watch box, a Notes-app entry that says "Submariner serviced 2019?", and a spreadsheet that opened once and was never updated. WatchLog is the dedicated record system that lives in your pocket instead of in your filing cabinet — every watch, every service visit, every regulation, every rotation, every receipt photo, on the same screen as the watch it belongs to. It is not a market-price tracker, not a forum, not a buying guide. It is the logbook your great-grandfather kept on paper, ported into something you'll actually update.

Why Collectors Need a Service Log

The moment you sell a pre-owned mechanical watch, the buyer asks one question: when was it last serviced? Without a record, the watch is worth less. With a record — dated service entries, photographed receipts, watchmaker names, costs — the watch is worth more, sometimes by the four-figure delta between "running fine" and "fully documented." WatchLog turns the service paperwork into a one-tap PDF you can email a buyer, attach to a sale listing, or hand to an insurance adjuster after a loss. The same record helps you on the buy side: when you're considering a pre-owned piece, you know exactly what a real service history looks like, because you've been keeping one on your own watches for years.

Mechanical Movement Accuracy: Why Seconds-Per-Day Matters

A healthy mechanical movement runs within a published range — COSC certifies -4/+6 seconds per day, METAS certifies 0/+5, most mass-market automatics run ±15 — and a watch's seconds-per-day deviation tells you, more reliably than anything else, when something has changed. A watch that ran +3 sec/day for two years and is suddenly running +14 is not "fine, it's mechanical." The mainspring is fatiguing, the lubricants are breaking down, or the regulator has drifted. WatchLog's accuracy chart plots every timing entry you log against a horizontal zero line so the trend is impossible to miss. Catch it at +14 and you spend $400 on a regulation. Miss it and a year later you spend $900 on a service that should have been routine.

Winder Rotation Strategies for an Automatic Collection

If you own three or more automatic watches, the winder problem is real. A piece sitting unwound for six months drains lubricant from the pivots, particularly on older calibers. A piece left on a winder running the wrong direction for an asymmetrically-wound rotor accomplishes nothing. A four-slot winder with eight watches needs a rotation schedule. WatchLog's winder registry lets you declare each winder (Wolf 4-slot Cub, Orbita Sparta, Buben & Zorweg, generic), assign each watch to a slot with direction (clockwise, counter-clockwise, bi-directional) and TPD (turns per day, usually 650–900 depending on caliber), and set a cadence reminder so the watch on slot 1 swaps with the watch in the safe every two weeks. Past rotation history is preserved so you can prove to yourself that the Heuer hasn't been parked since March.

Service Intervals by Brand: Rolex, Omega, ETA, Sellita

There is no single right service interval. Rolex publishes a recommendation of roughly ten years for modern calibers, citing improved lubricants and tighter manufacturing tolerances. Omega published an eight-year recommendation around 2017 for Co-Axial Master Chronometer movements, down from the older five-year industry default. Watches built on ETA 2824/2892 or Sellita SW200/SW300 ebauches — which covers a huge swath of the $500–$5000 market — generally do best at five-to-seven years. Vintage watches with hardened lubricant or worn gaskets may need attention every three years. WatchLog defaults to a five-year full-service target and a one-year pressure-test target and lets you override per watch. The defaults are a starting point, not a ruling. Your watchmaker, your manual, and your wrist time are the real authorities.

Vintage Watches and the Records Buyers Actually Want

A vintage watch without provenance is a coin toss. A vintage watch with a service history — even a partial one — is a different category of object entirely. When you buy a 1970s Speedmaster or a 1960s Submariner pre-owned, the dealer who keeps records charges 20–40% more than the dealer who shrugs. The records that move price: original purchase paperwork (or the closest thing to it), every documented service visit since acquisition, who did the work, what was replaced (crystal, gaskets, mainspring, balance staff), and photos of the case-back service marks if the watchmaker engraved or stamped one. WatchLog lets you attach all of that to the watch record, including extra photo slots for the papers, the receipt, and the case-back. When you sell, the PDF speaks for the watch.

Insurance Documentation for High-Value Collections

Once your collection passes the value cap of a renter's or homeowner's policy (typically $1500–$5000 for a single piece, $2500–$10000 for jewelry in aggregate), you need a scheduled rider on the policy or a dedicated valuables policy. Insurers want serial numbers, model references, purchase prices, current values, and ideally photos. They also want updates when you buy, sell, or have a piece serviced — because a watch that's been freshly serviced is worth more than the same watch overdue. WatchLog stores everything an underwriter asks for and lets you export it as a PDF the day you renew the policy. If you ever file a claim, the same PDF is the evidence the insurer needs to write the check at full value instead of a low settlement.

Photographing Case-Back Service Marks and Receipts

Watchmakers historically engraved or stamped the inside of a case-back with the date of service — a small set of numbers near the rim, sometimes with a logo or initials. Many independent watchmakers still do it. Manufacturer service centers usually don't engrave the case-back but always issue a printed receipt or service card. Photograph both. WatchLog supports multiple photos per service entry: snap the case-back stamp before you put the watch back together (or ask the watchmaker to send a photo), snap the printed service card, and snap the polished piece if a refinish was part of the service. Years from now, when you're selling, the photos are stronger evidence than a typed line that says "serviced 2022."

Privacy, Offline, and Backups

WatchLog stores every watch, every photo, every service entry, every winder assignment locally on your device. There is no account, no cloud sync, no telemetry on your collection in v1. The only network traffic is AdMob banners (Standard tier only) and the in-app-purchase round trip when you upgrade. For backup, Settings > Export Backup produces a single zip file containing the full database and every photo — save it to Google Drive, attach it to an email, copy it to a USB stick. Restore replaces everything on the device, so your collection is portable across phones but the publisher never holds a copy.

For Record-Keeping — Not Watchmaker Advice

WatchLog is a logbook, not a service manual. It does not diagnose movements, does not certify accuracy, and does not replace the judgment of a qualified watchmaker. A drifting accuracy chart is a hint to ask a professional, not a self-service repair guide. A service interval is a target you set, not a manufacturer's mandate. For anything safety-critical (water resistance before a dive, structural integrity after a drop, authenticity disputes) consult a qualified specialist. WatchLog's job is to remember everything you did so you don't have to.