What to Record in a Metal Detecting Logbook

A detecting log isn’t a diary of nice days out. It’s a learning system. The difference is what you choose to record — capture the right details and your log quietly tells you where to hunt, what settings to run, and how deep to dig. Capture nothing and every hunt starts from zero.

Here’s exactly what to record, and why each field earns its place.

Record these for every hunt

The hunt-level details set the context for everything you find that day:

• Date and time — so you can line finds up against seasons and conditions.
• GPS location — a pin beats a place name every time. Your best spot is often one corner of a big field, not the whole field. More on this in our GPS pins guide.
• Detector and settings — model, sensitivity, discrimination, and frequency mode. This is the snapshot you’ll want to repeat when a site produces.
• Duration — how long you swung. You can’t measure finds-per-hour without it.
• Weather and soil — both genuinely affect depth and signal quality. Damp ground often reads deeper than bone-dry.
• Notes — anything the data won’t capture. “Heavy iron near the gate.” “Cleaner signals after the rain.”

None of this takes long. The trick is doing it in the field, not from memory at home.

Record these for every find

The find-level details are where the real learning lives:

• Find type — coin, button, ring, relic, junk.
• Metal type — what it turned out to be.
• VDI reading — what your detector showed before you dug. Pairing the number with the actual find is how you learn your machine. See our VDI guide.
• Depth — many detectorists discover they’ve been digging too shallow once they track this.
• Keeper status — was it worth keeping, or trash? This one field powers your whole keeper-rate analysis.
• Photo — context you’ll never reconstruct later.

Yes, log the junk too. A pull-tab that read 32 is data — it teaches you what numbers to be cautious about at that site.

What not to record

This section matters as much as the last two, because the most common way a logbook fails is not neglect. It is ambition.

People design elaborate templates with twenty fields, use them meticulously for three hunts, find the whole thing exhausting, and stop. A log with fifty ordinary entries beats a beautiful one with four, every single time.

So be sceptical of any field that does not change a decision. Ambient temperature to the degree. Barometric pressure. Exact swing counts. A written narrative of the day. None of these will ever alter where you go or what you run, and each one adds friction to a habit that only works if it is frictionless.

The test is simple: if this field had a different value, would I do anything differently? If not, drop it. You can always add a field later; a habit you have abandoned is much harder to restart.

The sixty-second field routine

The thing that makes logging stick is turning it into a ritual attached to something you already do.

As you arrive: start the hunt entry. Site, time, detector, settings, and the weather as it actually is rather than as forecast. Ten seconds.

As you recover each target: the VDI you saw, the depth, what it was, keeper or not, and a photo if it is interesting. This is the one that must happen at the hole, because the VDI is already gone from your memory by the time you have refilled it. Fifteen seconds.

As you pack up: close the hunt, add the duration, and write one line of notes while the day is still in your head. “East end much quieter than last time. Iron heavy near the gate. Worth coming back after ploughing.” Twenty seconds.

That is the whole discipline. The reason it works is that none of the three moments requires you to remember to do it later.

Paper, spreadsheet, or app

All three work. They are good at different things, and it is worth choosing deliberately rather than by default.

Paper is unbeatable for reliability — no battery, no signal, no software. It is also pleasant in a way that spreadsheets are not, and plenty of long-standing detectorists swear by a notebook. The limitation is everything that comes after: paper cannot pin a location, hold a photograph, or tell you your keeper rate by VDI band without you doing the arithmetic yourself. In practice, that analysis rarely happens.

A spreadsheet solves the analysis problem and creates a data-entry problem. Typing rows into a phone spreadsheet at the edge of a field, in the rain, with cold hands, is miserable enough that most people end up doing it at home from memory — which quietly destroys the accuracy of exactly the fields that matter most.

An app built for it captures the location and the photo automatically, structures the fields so entry is tapping rather than typing, and does the aggregation for you. That is the case for DetectingLog — a complete hunt entry in under a minute, fully offline, syncing later only if you want it to. No signal in the paddock? It saves locally and catches up when you’re back.

The honest summary: use whatever you will actually use every time. A consistent paper log beats an abandoned app.

Why “boring” finds still matter

New detectorists often skip logging clad coins and trash because they feel unremarkable. That’s a mistake. The patterns that make you better come from volume, not from rare finds. Every logged target — keeper or not — sharpens the picture of what your detector’s signals mean in your soil. The unremarkable finds are the dataset.

There is a subtler version of the same problem worth naming: logging only the good days. It is very human to record a hunt that produced and skip the one that did not. Do that and every statistic you own is inflated, every site looks better than it is, and the comparison between two permissions becomes meaningless. Blank hunts are data. Log the zero.

Do it in the field, or it won’t happen

The single biggest reason logs fail: people put it off until they get home, and by then the details are gone. Log while you’re packing up, when the GPS pin, the depth, and the setting are all still fresh.

Back it up

A logbook becomes more valuable every year, which means the cost of losing it rises every year too. Three seasons of records is genuinely irreplaceable — you cannot reconstruct it, and no amount of effort will bring it back.

Paper burns and gets left on trains. Phones get dropped in rivers, which on a detecting trip is not a remote hypothetical. Whatever you use, have an answer to the question what happens if this is destroyed tomorrow? Optional cloud sync, a periodic CSV export, or simply photographing your notebook pages will all do. Just have one.

Plan the next hunt from the last one

A log isn’t only a record of what happened — it’s the raw material for deciding where to go next. Reviewing which conditions produced at which site turns your own history into a planning tool, which is the whole idea behind our pre-hunt checklist.

Turning a log into better hunts

Once you’ve got ten or so hunts down, the log starts paying you back:

• Best sites rise to the top — ranked by keeper rate, not gut feeling.
• Productive settings prove themselves — you’ll see which configurations pull keepers from which soil.
• Depth patterns appear — and often reveal targets you’ve been walking over.

You don’t build any of that by hand. The analytics do the aggregation; your only job is to log consistently and keep your records private.

Your records have a use beyond your own hunting, too. If you find something reportable, the findspot and depth you captured at the hole are exactly what a Finds Liaison Officer or heritage authority will ask for — as covered in our guide to recording finds with the PAS. A good log turns that conversation from an interrogation into a read-out.

Start with one hunt

Don’t try to backfill years of history. Just log the next hunt, then the one after. Five entries in, you’ll start noticing things. Twenty in, you’ll wonder how you ever hunted without it.

Start with one hunt — your future self will thank you.