Documenting a site visit with no signal

You can document a whole site visit with no signal, as long as the app stores every capture on the phone and syncs later, and you do the two jobs that need a connection before you arrive and after you leave. Basements, plant rooms, rural sites and new concrete shells all kill reception. The visit does not have to stop for any of them.

What changes offline is the order of work. Anything you would normally look up or send on the spot has to happen at the gate instead.

Test the app in airplane mode before the visit

Most field apps say they work offline. They mean different things by it. Some cache the project list but refuse to open the camera. Some take photos but drop the note you typed if the upload fails. Some need a connection to transcribe a voice note.

Find out at your desk, not in the basement. Turn on airplane mode, open a test project, and do one of everything: a photo, a voice note, a sketch on a photo, a typed note. Force quit the app. Open it again and check that all four are still there. Then turn airplane mode off and watch them upload.

Load what you need while you still have signal

Anything that lives on a server is out of reach once you are underground. Before you lose signal, usually in the car park:

• Create the project for the visit, so you are not fighting a sign-in screen later.
• Download or screenshot the drawings, the previous report and any open items you are checking.
• Note the address, the client contact and the access arrangements somewhere that does not need a network.
• Charge the phone, or bring a battery. Searching for a signal drains it faster than normal use.

If the visit is a re-inspection, the previous report matters most. You cannot check that item 14 was fixed if item 14 is on a server you cannot reach.

Capture each observation in one step

Offline work goes wrong at the matching stage. Photos land in the camera roll, notes go in a notebook, and at the desk you are guessing which crack belongs to which sentence.

Keep each observation together at the moment you make it. Take the photo, then attach the note to that photo, by voice or by typing, before you take the next one. In Sitewise the photo, its voice note, any sketch drawn on it and the typed note sit together in one capture, and each capture gets a timestamp and, if location is on, a GPS pin. None of that needs a connection.

One observation per capture. A photo of a wall with three problems on it is three captures, or one capture with the three problems numbered in the note.

Say the location out loud, because the pin may be wrong

GPS does not need cell signal. The phone works out its position from satellites, so the pin usually still arrives on an open site.

Indoors and underground it is less reliable. A pin taken in a basement plant room can land in the street outside or fail altogether. Treat the pin as a backup and put the location in the note: level, room, gridline, the nearest fixed object. "Level B2, pump room, north wall, left of the riser door" will still lead someone to the spot in five years, long after anyone remembers which dot was which.

Dictate short notes and check them before moving on

Voice notes are the fastest way to capture with your hands full, and they work offline. Sitewise records each one against its photo and transcribes it with Apple's speech recognition.

Transcripts get room numbers, product names and anything said over a compressor wrong. Read each one before you leave the spot, while you can still see what you meant. Fixing "level to" into "level 2" takes three seconds on site and a phone call a week later.

Keep each note to one observation: where, what, how bad, what next. The voice notes guide goes through the wording in more detail.

Sketch on the photo instead of describing the geometry

Some things are hard to say. Where exactly a crack runs, which of three pipes is weeping, how far a downpipe sits from the corner.

Draw it. A circle and an arrow on the photo cost nothing and need no signal. On iPad, sketches take Apple Pencil. On a Pro iPhone or Pro iPad with a LiDAR scanner, two taps in the camera put a measured dimension on the photo, which beats "roughly 300 mm" in a note.

Do not judge the visit by the upload icon

Offline, every capture shows as waiting to sync. That is normal. Resist the urge to walk back to the stairwell every twenty minutes to push uploads through. Each trip breaks your route, and the captures are already safe on the phone.

Do one check before you leave the dead zone. Scroll the project and confirm that every observation you meant to record is there, with its note. Missing a capture is the one offline failure you cannot fix later, because you are no longer standing in front of the thing.

Sync and send from the car park

Once the phone is back on cell or Wi-Fi, Sitewise syncs the project in the background. Give it a few minutes on a slow connection, since photos are the heavy part.

Then build the report. Pick the captures that tell the story, generate the PDF or DOCX and email it to the client. The report is built from the uploaded captures. If any of the photos you selected are still uploading, Sitewise says so before you generate, because they would appear as placeholders. Wait for the upload and you get a complete report.

Sent from the car park, the report reaches the client the same day, as it would from a site with full signal.

Know what offline does not cover

An offline app protects your capture. It cannot do things that need someone else. You cannot email from the plant room, check an item against a colleague's live punch list, or pull up a drawing you never downloaded.

Sitewise is a capture and report app for iPhone and iPad on iOS 26 or later. It does not do scheduling, budgeting, CAD or drafting, or e-signature, and there is no Android or web version. A crew editing one shared plan set in a tunnel needs a plan management tool instead.