Tide Tool FAQ 

Tide Computation Software
for Palm OS Handhelds 

Tide Tool Home Page
Locations Covered
Download Tide Tool

Page last updated June 23, 2009  

A version of Tide Tool is available to incorporate the 2007 U.S./Canada Daylight Savings Time change and more recent NOAA tide data.  It is labeled a beta but has been out for a couple of years without complaints.


Most Frequently Asked Questions See also: Program Instructions On-Line

FAQs about Locations and Tide Predictions

FAQs about Getting and Loading Tide Tool FAQs about Running Tide Tool

Most Frequently Asked Questions:

Q: Will Tide Tool run on the Palm Pre?

A:  It will not run directly, but it reportedly runs under the Classic emulator (see photo).

Q:  Do you have Tide Tool for Windows Mobile, the Blackberry, iPhone, Pocket PC. or other non-Palm computer or phone? 

A:  Sorry. Tide Tool only runs under PalmOS (version 2 or later) for the Palm and other handhelds (including the Handspring Visor) running Palm OS.

    It does not run on Windows Mobile, the Blackberry, Windows CE, or any other platform that does not run the Palm OS.  And - sigh - not the iPhone.  My apologies to all the users who have migrated to these devices.  But I don't have the time to keep the Palm version up, let alone port it to hardware I don't own.

    I will never port it to another platform.  When mobile versions of Windows came out, I had no interest in supporting Microsoft.  If you care why, see my rant below (after which you might look at this program.  Or check out StyleTap, a program that reportedly runs Tide Tool and many other Palm OS applications on Windows Mobile and Pocket PCs.).  Now that there are many worthy portable devices, I have other priorities and just don't have the time or inclination for a major programming effort.

    The source code is available, of course, and anyone who wants is invited to try to port it to other platforms. But the resulting program has to be freeware; see the GNU Public License

Q:  Does Tide Tool run on my new PDA?  On my Treo?  

A:  Tide Tool runs on everything running the Palm operating system, version 2 or later. This includes every Palm shipped since 1997, the Handspring Visor, those Treo phones that run Palm OS, etc.  If it doesn't work, let me know - but it has worked on every new Palm OS device so far.  Palm OS version 5 requires a recent version of Tide Tool; see this FAQ.

     Does it work on your new PDA or cell phone with the very latest Palm operating system?  Almost certainly.  Please try it before emailing me.

     Tide Tool does not run on PDAs or cellphones running Windows CE, Windows Mobile, or anything other than a Palm OS.  See this FAQ.

     Palm OS - yes.  No Palm OS - no.

Q:  My favorite location is not in Tide Tool. Please add it (or put it back).

A:  See the location FAQs below.

Q:  The tides shown for my location don't agree with the ones in my local newspaper. 

A:  See the location FAQs below.

Q:  When I hit the Place button, the program freezes, or resets, or gets a fatal error message.

A:  You have too many regional databases loaded.  See the FAQs about running Tide Tool, below.

Q:  I don't have a Palm-compatible handheld. Please send me Tide Tool for my Frobozz Hexium 10 computer.

A:  See the FAQs about getting Tide Tool below.

FAQs about Locations and Tide Predictions:

Q:  The tides shown for my location don't agree with the ones in my local newspaper. 

A:  Tide Tool uses the database from XTide, and a prediction method that is similar to XTide's. This prediction method is pretty good for North America (usually within a few minutes) but not so good elsewhere. In some parts of Australia it can be off by an hour or more. Also, the data in XTide has been obtained on a zero budget. In some places (including Australia), the best tide data is produced by for-profit companies, not by the government, and is not generally available and definitely not free.

     First, check Tide Tool against XTide. You can use any of several Internet sites running XTide, such as this one. If XTide and Tide Tool differ by more than a minute or two, let me know - I have a bug. If they're the same, then that is the best Tide Tool is going to do. Sorry.

    The Internet pages may have more than one data set for your location. Tide Tool uses only the first one, to save space. If one of the other data sets looks better, please let us know, and include at least the tides for several dates from your local source.

Q:  The tides shown are similar to the ones in my local newspaper, but the heights are all off by the same amount.

A:  Tide heights are given with respect to a zero reference height, called the "datum".  Chances are that Tide Tool is using a different datum from your other predictions.  Once you determine the difference between the two datums at a particular location, you can adjust all predictions by the same amount. 

 Q:  Does Tide Tool cover my geographic area?  

A:  The databases in the current version cover the whole world, with all the locations I have data for.  Check the location list for the places you care about.

Q: Where are all the tides for the United Kingdom? What happened to my location?

A: For some years, the U.K. Hydrographic Office prevented us from using the tidal prediction data, which they claim to own, for certain locations, including the entire British Isles and some other locations worldwide. Fortunately, locations in Great Britain have been restored in Version 2.2, which you can download.   Unfortunately, this doesn't help Eire or about 50 other locations around the world.  See more details here.

   If you have access to tidal data for those places, with permission to use it, you can help us out - see the next question.  

Q: My favorite location disappeared from the latest release (or beta)!  Put it back now!

A:  New releases try to use the latest data.  NOAA is the U.S. data source, and they make changes.  Between Tide Tool 2.2 and 2.3, they made a lot of changes.  So quite a few locations were added or disappeared.  

     Also, a number of locations have been renamed in Tide Tool to be more consistent with the NOAA names.  So use the Find button on the Place screen and search for it by latitude and longitude.  (If it's really gone, this will show you the next closest location.)

     Then check the NOAA predictions pages, and the harmonic constituents page.  If your location is no longer on one of those, it's been downsized.  Sorry.

Q:  You have a database for my area, but my favorite location isn't in it.  Can you please add it? 

A:  No, but you can. Only, it will take a while.

    Tide Tool uses the harmonic constant database, and offsets database (in version 2), maintained by Bob Kenney for Dave Flater's program XTide.  So I don't add locations; I just use Dave's.

    To add your location to Tide Tool, you will need either a set of harmonic constants for the location, or a set of offsets to compute the tide or current based on a known reference station which is already in Tide Tool (and most are).

    Put your data in the correct format (see the XTide page on harmonic constants and offsets) and email it to Bob. It will eventually make its way into Tide Tool.

    There is one other possibility.  Given the tide height measurements taken at a location every hour over a year's time, our database keeper could derive the harmonic constants. So if you can find academic or research sites that can furnish that data and can grant permission to use it, by all means let me know.

Q:  I don't have data for my favorite location. But I have a commercial tides and currents program on my PC and it has my location, so I know the information is available.  Can you please add it? 

A:  The publishers of your program probably obtained the harmonic constants or offsets from NOAA, or got them somewhere else, possibly for pay. You can try to obtain and send them to Bob Kenney for incorporation into XTide. They will eventually migrate into Tide Tool.  See the XTide FAQ for more information, particularly his page on harmonic constants

Q:  You have tides for my location, but not currents. Can you please add them? 

A:  Currents require their own data set. Just because there is tide data for a location doesn't mean there is also current data. In fact, there almost never is. Unfortunately there are very few current data sets outside North America in the XTide data base. If it's not there, I don't have it.

Q:  When are you going to add the ability for me to enter my own subordinate locations?

A:  This has been taken off the "future features" list. Chances are that if predictions are available locally for your location, you can find a set of offsets for that location from a reference station. Since Tide Tool can now cope with offsets, I would prefer that you send Bob your offset data so that it can get into the XTide database and everyone can use it. Yes, it will take longer for you to get Bideawee Cove into your Palm. But you're already benefiting from the data everyone else contributed. Now it's your turn.

FAQs about Getting and Loading Tide Tool

Q:  I don't have a handheld computer, but I do have a personal computer or a workstation.  Please send me a version of Tide Tool for my machine. 

A:  You don't want Tide Tool for your machine (and a lucky thing too, because it doesn't exist so you can't have it.)  You want XTide, which has been ported to a number of machines.

Q:  I am having trouble downloading Tide Tool.

A:  Try another download site.

Q: I downloaded the Tide Tool zip file. Now what do I do?

A: Oh, a newbie, huh? Well, we were all newbies once, so you're entitled to a little help. First unzip the file you downloaded. (If you need an unzipper, WinZip is the standard, and Stuffit Expander is free, though it doesn't compress.) Then use your browser to look at the readme file. Then install the three files - tidetool.prc, tideargs.pdb and the .pdb database file for your region - using the Install function of your Palm Desktop program.

Q: I don't understand how to do all that.

A: Sorry, but if I had the time to write a full-blown tutorial, I'd use it to work on Tide Tool instead. (No, I wouldn't. I'd go boating.) Please look elsewhere for more help.

Q: The Tide Tool icon doesn't appear in the Program Launcher.

A: Okay, let's try this once more.  You.  Need.  To.  Install.  Three.  Files:

  • tidetool.prc
  • tideargs.pdb
  • and at least one of the regional .pdb database files

Q: I loaded the three files, but the program says that one of the database files has not been loaded.

A: Perhaps you are using version 2.1c or earlier, and loaded the files into expansion memory.  Expansion memory only works with Tide Tool version 2.2 and later.  Load the files into RAM, or update to the latest version.

Q: Some of the database files are missing after I unzip the distribution file.

A: There are twp possible causes.  Sometimes Windows confuses two similar long filenames.  Or you might be using an old unzip program that can't handle long filenames.  Did you notice any error messages like

PKUNZIP: (W10) Warning! can't create: U.S. West Coast.pdb
PKUNZIP: (W18) Warning! Canada (Central West).pdb already exists. Overwrite (y/n/a/r)?

Users have also reported problems using the built-in zip features of Windows XP.  

A fix was attempted beginning in version 2.1c.  (The files have been renamed yet again.)  If you are using an older version, try updating.  (Delete old files from your PC and Palm first.)

Since then I haven't heard any complaints.  But if you run into this, please let me know.  Then try creating a new folder, copying all the Tide Tool files to that folder, and installing from there.  Or try downloading a more recent unzipper like WinZip or Stuffit Expander.

Q: I can't install one of the database files.  When I select it the Installer says it doesn't exist.

A: Occasionally Windows gets confused about files with similar long filenames.  Try renaming the database file to something short and simple, but still with a .pdb extension,  and see if the Installer will load it then.

The database files have been renamed several times to try to avoid this issue.  If you run into it on the current version, please let me know.

Q: I installed the Alaska Airlines schedule app and now Tide Tool doesn't work with the Alaska tide database.

A: For some reason, Palm OS can't distinguish between the two databases, even though they're from different applications.  Try installing the current version.  It will coexist with Alaska Airlines.  (Just don't order the fish.)


FAQs about Running Tide Tool

Q: When I try to run Tide Tool, I get a fatal error message.

A: Couple of possibilities:

  1. Did you install three files? You need tidetool.prc, tideargs.pdb, and at least one regional database file. See the readme file in the Tide Tool distribution.

  2. Did you load the files onto an expansion card (SD or MMC card, memory stick, etc), and are you using version 2.1c or earlier?   Expansion memory only works with Tide Tool version 2.2 and later.  Update to the latest version.

  3. If you had an earlier version of Tide Tool installed, delete it from your Palm and then reinstall the new one.

  4. Are you using JOT?  Earlier versons make Tide Tool crash.  It works with version 2.01 and later.  For a while the company was issuing free upgrades, but that link is no longer valid.  JOT has since been incorporated into Graffiti2, so you might not need it any more.  

  5. Macintosh owners may get a fatal error message, usually (but not always):

        tidedb.c, Line:461,
        assertion 'amp-
        placedata 'failed

       If you are using Stuffit to unzip tidetool.zip, go into the Stuffit preferences.  Under Cross Platform set "Convert text files to Macintosh format" to "Never".  Then unzip tidetool.zip again, delete Tide Tool from your Palm and reload it.
       If you are using ZipIt, under the Zip menu bar set  "Add/Strip Linefeeds" to off (unchecked).  (This workaround was given to me; if the command is different in your version let me know and I'll add it.) 
       If you are using a different unzip program, look for a setting relating to text files, end of line characters, etc. and play with it.  Or try installing Stuffit Expander (it's free) and follow the instructions above.

  6. FWIW, a user reported a fatal error in selecting a new place.  Removing the Zagat Restaurant Survey application from his Palm made the error go away.   

  7. A Visor user reports that after adding a new regional database, he gets a crash.  His workaround is to delete the entire application from the Visor and reload all the files at once.

  8. A Sony Clié user reports that his fatal error was caused by using the high resolution mode.  If High Resoution mode is selected in the HiRes Preferences menu, it must be deactivated for the Tide Tool application.  Alternatively, a utility called SwitchDash can be used to automatically configure resolution for this and other resolution-sensitive applications.


 If you get a crash that is not related to one of the above causes, please let me know.  Include the version of Tide Tool you are loading, what error message you get, and what you did up to the time you got it.

Q: Tide Tool does not work on my Tungsten (or other Palm OS 5 device).

A: Download the latest version, which does work on OS 5.

Q: An error message says a database file is from an older version of Tide Tool.

A: This is a common problem, and appears to be due to the Palm desktop preserving older versions of databases and reinstalling them.

    Many users report that if they delete Tide Tool from the Palm and reinstall it, and repeat this two or three times, they finally get rid of the error message.

    Another solution is to find and delete the old files from your PC.  From the Windows Start menu, do a Search for - Files and Folders, and search for *.pdb.  You should find some Tide Tool regional databases in folders named Backup or some such.  Delete them, then unzip Tide Tool again and load onto your Palm.

    One user reported solving the problem by these steps:  (1) Delete Tide Tool; (2) Load just tidetool.prc and tideargs.pdb; (3) Run Tide Tool and get the error that no databases are loaded; (4) Load the desired database.  If at step (3) you get the "older version" message instead, try one of the other solutions above.

Q: Parts of the graph are so dark (or so light) that they are not visible.

A: Either set the contrast control so that the graph looks better, or turn off grayscale display: Menu | Edit | Preferences and uncheck "Display shades of gray". (Only applies to version 2.1 and later)

Q: When I hit the Place button, Tide Tool displays "Sorting ..." and takes a long time to display the places. 

A: Tide Tool is sorting the place list.  It may look frozen, but it's working.  The controls work during the sort (in Version 2.1 or later), so you can cancel or change without waiting for the sort to finish.  (If you have a whole bunch of databases loaded, maybe it really is frozen.  See the next question.)

    Still, the sort can take a long time, particularly if you have several regional databases loaded. And if you have a lot of them, you may get a fatal error or a crash.  

    There are several workarounds for this.  You can use the Previous checkbox on the Place screen to avoid the sort. Select your favorite places once, and then keep Previous checked until you need a place not on the list.

    Disable some of the regions. Use Menu | Edit | Regions, and change "In Use" to "Disabled" for the regions you don't need.

    Deleting or disabling some of the databases will speed the sort up a lot. If your regions have lots of subordinate locations, so will turning them off using Menu | Edit | Preferences. Of course, then you won't get all the available locations.

Q: When I hit the Place button, the program freezes, or resets, or gets a fatal error message.

A: Tide Tool ran out of memory trying to sort the location list. You have too many regional databases loaded.  

    Maybe you loaded everything that came in the Tide Tool distribution.  You only need to load the database file (or files) for the regions you will use.

    Disable or delete some of them by Menu | Edit | Regions. To disable a region, use Menu | Edit | Regions, and change "In Use" to "Disabled" for the regions you don't need. Alternatively, try turning off subordinate locations using Menu | Edit | Preferences. This will give you only the most reliable locations and reduce the amount of memory the program uses.

Q: On my HandEra 330, the graphs look funny.

A: The HandEra has a 240x240 screen. The Palm standard is 160x160. Although the HandEra tries to display most programs accurately, it can't cope with the drawing method used by Tide Tool. There's no reasonable workaround for me, so it will stay that way. No doubt more devices with higher resolution screens will come on the market, and I'll revisit the issue once there are standard ways of dealing with higher resolutions.

Q: I put the databases on a memory expansion card, but Tide Tool doesn't see them.

A:  Download Tide Tool 2.2 or later, which does support both program and database files on expansion cards.  Earlier versions did not.

Q: I put the databases on a memory expansion card, but when I run the program it gets copied into RAM, and the Info / Regions command says they're in RAM.

A:  Are you using ZLauncher, or a similar utility?  ZLauncher assumes that programs are not expansion memory aware.  So it copies all their databases  temporarily into RAM to run them.  (This is not completely bad.  It will slow down the launch, but having the databases in RAM will speed up the Place screen.)

   If you want to put some or all of the Tide Tool files on an expansion card, use the Palm Desktop installer to do it.  The Palm OS launcher won't move database files, only the program files.  Even ZLauncher will not move database files into the default directory (/Palm/Launcher) where Tide Tool looks for them.

Q:  I got the error "Could not delete the database from the expansion card."

A:  This can happen when the database has the wrong filename on the expansion card.  I've seen this occur when the database is placed in the Install tool by double-clicking it.  You can delete the database from the Launcher.  Use the App / Delete command and select Delete from: Card.

Q: Why isn't Tide Tool displaying tide coefficients?

A: The coefficient (not to be confused with harmonic constituents or coefficients) is a peculiarly French tide measurement.  It is a number between 20 and 120 that indicates the relative height of a high tide.  It is displayed only for ports on the Atlantic Coast of France.  It wouldn't be much use anywhere else.

   If the coefficient doesn't display for you, even in those ports, use the Edit | Units menu and under Coefficients check Display.

Q: Why does HotSync back up Tide Tool database files on my PC?

A: There was a time when HotSync didn't back up installed software, but apparently more recent versions do. So you should find copies of all the Tide Tool files in your backup directory. 

  If you are compulsive about reducing clutter on your PC, you could delete all the Tide Tool files from your backup directory before upgrading to a new version of Tide Tool, because some file names have changed over time.

Q:  I just got a new Palm (or upgraded to PalmOS 3.3 or later) and the Tide Tool display is full of weird euro characters.

A:  Download and use Tide Tool 2, which copes with the euro symbol introduced in PalmOS 3.3.

Q: The Cache Info feature prints garbage all over the screen.

A: That's not a feature, it's a bug. :-) No, actually it's a debugging printout in Tide Tool 1.2b1 that really shouldn't have been left in there. I was in a rush to post a beta to fix the euro bug, and was too lazy to take it off the menu. Ignore it. Anyway, you should be running the latest version.

Q:  I downloaded Tide Tool and installed it according to your instructions, but the hotsync log says "Deleted invalid file somethingorother.pdb".  When I try to start Tide Tool on my Palm, I get the message "There is no locations database file installed."  Please send me a working version.

A:  If you're downloading from a Mac, you may be encountering a very old bug with Mac backup and restore of .pdb files.  Long ago, U.S. Robotics posted a Mac Conduit Manager 1.01 update that was supposed to fix this problem. 

     Another possible source of this error message is that you are trying to run Tide Tool on PalmOS version 1, on a Pilot 1000 or Pilot 5000.  These machines can't run Tide Tool without a hardware upgrade

Q:  Can you make the program smaller? 

A:  Only by taking out features or places.  :-)

Tide Tool was written by Walt Bilofsky
After you've read the FAQ, go ahead and email me.


Windows CE rant:  Here's why I won't port Tide Tool to any other platforms, and especially not to Windows CE.

I did Tide Tool because it looked like a fun project, and there were free development tools around and a supportive development community.  I did it for free.  I have other priorities in my life, and porting to another platform would be more work than I am willing to undertake.

I absolutely won't port it to Pocket PCs or any device running Windows CE.  I can't get excited about donating a lot of work to support Microsoft's attempt to take over yet another product area that small innovative companies opened up for him.

I am sympathetic to people who bought Windows CE handhelds.  Many of you did that so you could use Word or Excel.  See?  Microsoft is leveraging their dominance in office applications to try to take over the handheld market.

The inventors of the Palm made out OK.  But how many other innovations are discouraged because the reward of success is to have Microsoft eat your lunch?  It may make sense for a lot of users, but I won't contribute to it.

There.  I feel much better now.