Page 1 of 1
Swift AI GPS Backfill Tool for MacDive
Posted: Thu Feb 26, 2026 3:45 am
by Bollar
I wrote a small utility that extracts GPS coordinates from the Shearwater Swift AI transmitter data already sitting in your MacDive database and backfills them into your dive sites.
If you dive with a Shearwater computer paired with a Swift AI GPS, your dive computer records entry and exit GPS on every dive. MacDive imports the raw data but doesn't extract the embedded coordinates — so those dives end up without map pins. This script fixes that.
What it does:
- Scans your MacDive database for Shearwater dives with raw data but no GPS
- Decompresses the dive computer memory and extracts entry/exit coordinates
- Creates dive sites with map pins at the entry location
- Reverse-geocodes to fill in country and region
- Appends both entry and exit coordinates to your dive notes
- Dry-run by default, automatic backup before any writes
Requirements: Python 3, no dependencies to install. Quit MacDive, run the script, reopen MacDive.
Code: Select all
python3 macdive_gps_backfill.py # preview
python3 macdive_gps_backfill.py --apply # write changes
If this doesn't work for you, please let me know — I've only tested it on my own database.
I've tried the alternatives and I'm not ready to move on from MacDive yet. This will let me hang on while looking for an alternative, or perhaps writing one myself.
The GPS record format was identified from the
https://www.libdivecomputer.org/ open-source library, which added Swift AI GPS support in its Shearwater parser. The decompression algorithm is also from libdivecomputer. Great project — worth knowing about if you're into dive computer data.
Re: Swift AI GPS Backfill Tool for MacDive
Posted: Thu Feb 26, 2026 6:15 am
by nick
Clever workaround.
I am picking up one of these this weekend, will likely do some dives with it in a month or so, and then do an update to support it.
Re: Swift AI GPS Backfill Tool for MacDive
Posted: Mon Mar 02, 2026 11:17 pm
by shoule
@nick I am going on a liveaboard in less than 2 weeks. As my buddy and I will be doing a lot of dives in a short time (with Swift GPS), we are willing to try a beta version if that is something possible.
Re: Swift AI GPS Backfill Tool for MacDive
Posted: Sun Apr 05, 2026 4:45 pm
by tcherna
Did you try editing the locations or only used the information that was populated by the tool? I find if I edit the locations then MacDive will crash.
Code: Select all
Date/Time: 2026-04-05 16:34:51.3357 +0800
Launch Time: 2026-04-05 16:34:50.8647 +0800
Hardware Model: MacBookPro18,4
OS Version: macOS 26.3.1 (25D771280a)
Release Type: User
Crash Reporter Key: A3DCED2D-DFE1-2770-660F-14616C1F736D
Incident Identifier: 2B28E6C6-1AB9-4614-9990-8D04294ADCA6
Sleep/Wake UUID: 60086C5C-ADE5-401C-9BD3-7551E63C7656
Time Awake Since Boot: 1800 seconds
Time Since Wake: 1305 seconds
System Integrity Protection: enabled
Triggered by Thread: 0, Dispatch Queue: com.apple.main-thread
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Reason: *** -[__NSDictionaryM setObject:forKeyedSubscript:]: key cannot be nil
Termination Reason: Namespace SIGNAL, Code 6, Abort trap: 6
Terminating Process: MacDive [1702]
Application Specific Information:
abort() called
Last Exception Backtrace:
0 CoreFoundation 0x19b9438f0 __exceptionPreprocess + 164
1 libobjc.A.dylib 0x19b41a418 objc_exception_throw + 88
2 CoreFoundation 0x19ba703dc -[__NSDictionaryM setObject:forKeyedSubscript:] + 1184
3 MacDive 0x1001367ec 0x10012c000 + 42988
4 MacDive 0x100136394 0x10012c000 + 41876
5 MacDive 0x100136178 0x10012c000 + 41336
6 AppKit 0x1a0498a24 -[NSIBObjectData nibInstantiateWithOwner:options:topLevelObjects:] + 864
7 AppKit 0x1a068310c -[NSNib _instantiateNibWithExternalNameTable:options:] + 332
8 AppKit 0x1a06832a8 -[NSNib _instantiateWithOwner:options:topLevelObjects:] + 132
9 AppKit 0x19fd34388 -[NSViewController loadView] + 296
10 AppKit 0x1a036e990 __39-[NSViewController _loadViewIfRequired]_block_invoke + 60
11 AppKit 0x19fd31a10 NSPerformVisuallyAtomicChange + 108
12 AppKit 0x19fd34250 -[NSViewController _loadViewIfRequired] + 116
13 AppKit 0x19fd34190 -[NSViewController view] + 24
14 MacDive 0x10014eeac 0x10012c000 + 143020
15 MacDive 0x10014b164 0x10012c000 + 127332
16 AppKit 0x1a0498a24 -[NSIBObjectData nibInstantiateWithOwner:options:topLevelObjects:] + 864
17 AppKit 0x19fcfcf88 loadNib + 340
18 AppKit 0x1a069c944 +[NSBundle(NSNibLoading) _loadNibFile:nameTable:options:withZone:ownerBundle:] + 1064
19 AppKit 0x19fdbaf68 -[NSWindowController loadWindow] + 300
20 AppKit 0x19fdbad20 -[NSWindowController window] + 80
21 AppKit 0x1a0d5eb6c -[NSWindowController showWindow:] + 44
22 MacDive 0x100148000 0x10012c000 + 114688
23 CoreFoundation 0x19ba2875c -[NSSet makeObjectsPerformSelector:] + 176
24 AppKit 0x1a0498a04 -[NSIBObjectData nibInstantiateWithOwner:options:topLevelObjects:] + 832
25 AppKit 0x19fcfcf88 loadNib + 340
26 AppKit 0x1a069c944 +[NSBundle(NSNibLoading) _loadNibFile:nameTable:options:withZone:ownerBundle:] + 1064
27 AppKit 0x1a069cc64 -[NSBundle(NSNibLoading) loadNibNamed:owner:topLevelObjects:] + 180
28 AppKit 0x1a069c3e0 +[NSBundle(NSNibLoading) loadNibNamed:owner:] + 300
29 AppKit 0x19fcf455c NSApplicationMain + 496
30 dyld 0x19b48dd54 start + 7184
Re: Swift AI GPS Backfill Tool for MacDive
Posted: Sun Apr 05, 2026 4:57 pm
by tcherna
The biggest test that something is wrong in the new site data is that even after populating the country/location/site name, the site name appears blank and does not appear as a drop down as normal. I'm still using the tool to log the gps coords so I can manually enter them.
I can share corrupted dbs to anyone who wants
. Also, thanks for making the script and having it do backups too
Re: Swift AI GPS Backfill Tool for MacDive
Posted: Sun Apr 05, 2026 5:04 pm
by Bollar
Ah, I didn't add a name to the DB before geolocating the position. I have a replacement on GitHub now that should work. Please let me know either way.
Just in case it wasn't obvious, you do need to restore the backup and run on the original MacDive database.
https://github.com/rbollar/macdive-swiftai-gps
Re: Swift AI GPS Backfill Tool for MacDive
Posted: Sun Apr 05, 2026 7:03 pm
by tcherna
I'm not sure that's all it, as now MacDive will crash just after running the script. Any reason you aren't passing the mod time any more? Also I'm wondering if it needs real defaults other than None
Re: Swift AI GPS Backfill Tool for MacDive
Posted: Mon Apr 06, 2026 2:55 am
by tcherna
Here's a version which seems to work. It matches the default strings when creating a site in macdive, adds the required uuid, and creates a site name that makes it easy to edit (by appending the dive number from the modified created sites)
Code: Select all
# Create new ZDIVESITE
site_pk = next_site_pk(db)
site_uuid = str(uuid.uuid4()).upper()
site_name = f"New Site {dive_num}"
now = time.time() - 978307200 # Core Data epoch
db.execute("""
INSERT INTO ZDIVESITE
(Z_PK, Z_ENT, Z_OPT, ZGPSLAT, ZGPSLON,
ZCOUNTRY, ZLOCATION, ZBODYOFWATER, ZMODIFIED, ZNAME, ZUUID)
VALUES (?, ?, 1, ?, ?, ?, ?, ?, ?, ?, ?)
""", (site_pk, site_ent, entry_lat, entry_lon,
(geo[0] if geo and geo[0] else "New Country"),
(geo[1] if geo and geo[1] else "New Location"),
(geo[2] if geo and geo[2] else None),
now,
site_name,
site_uuid
))
Re: Swift AI GPS Backfill Tool for MacDive
Posted: Mon Apr 06, 2026 3:55 am
by Bollar
Great!
You did the hard work and the current version incorporates the solution you identified along with a guard to prevent running if a .bak exists. The other difference is that we geolocate the coordinates, if possible.
Re: Swift AI GPS Backfill Tool for MacDive
Posted: Mon Apr 06, 2026 10:04 am
by tcherna
Thanks. Also greetings from the Similan Islands