TideFinder is a tide search program based on the GPL licensed XTide
software. Unlike most ocean tide forecast programs, TideFinder does not
give you the height of the tide at a given time and location, nor does
it give the times of the high and low tides. Instead, TideFinder lets
you FIND the tide you want, when you want it.
Suppose you want to hike to the lighthouse at Dungeness Spit on the
North Olympic Peninsula. The walk can be dificult when the tides are
high. There isn't much beach, and what beach there is will be rocky and
hard going. The round trip walk takes at least three hours, and usually
closer to four. If you want to reach the lighthouse around low tide,
you have to start an hour and a half to two hours before low tide. You
may also have other constraints, like driving time or dinner
engagements.
The traditional way to pick a good day to try for the hike is to scan
the tide tables looking for a low tide in the late morning or early
afternoon. This can be tedious. Tide tables are boring. Computers
should save you work, not give you work.
How To Use TideFinder
With TideFinder, you start by specifying the location. There is a
search facility which searches the XTide database and lets you choose a
location from the search results. Then you give the start and end date,
the earliest time and the latest time, the high and/or low bounds for
the tide, and the minimum duration for the tide. TideFinder will invoke
XTide to compute the tides for the days indicated in fifteen minute
increments. It then checks for a tide that meets your conditions with
regard to time and height. You can view the results as a list, in a
calendar format or you can check the tides graphically.
TideFinder is based on XTide, but it uses the tide program, not the
xtide program, so you do NOT
need to have X Windows installed or running. The download includes a
version of tide compiled for OS X. There is also a link to the source
code for XTide if you want to roll your own.
Setting up TideFinder
When you first start up TideFinder, it will not be able to find the
tide component of the XTide program or the harmonics file. To tell
TideFinder where these items are, use the Tide > Set Tool Path menu
item. It will ask you for a folder. This folder should contain the tide
program and either the harmonics.tcd or harmonics.txt file.
Once you have specified the folder, quit TideFinder and then restart
it. It should run tide and get the list of available locations.
Setting the Location
To set the location, start by typing part of the location name into the
Search For field. TideFinder uses the XTide database, so not every
location will be found. Hit RETURN and the search results will appear
in the pop up menu below. Just select the location you want from that
menu. If you are having trouble, try typing in the name of a state or
country.
The Start and End Day
TideFinder searches over a range of days for the desired tide. Enter
the first and the last day you are interested in.
The Earliest and Latest Time
TideFinder lets you find the desired tide between the earliest and
latest times. So, if you want the tide to be around mid-day, you might
specify an Earliest time of 11:00 and a Latest time of 2:00. the times
may simply be hours, or hours and minutes separated by colons or
periods. They may be in 24 hour format if you use a colon or period. If
there is an AM or PM after the hour, or you use 24 hour times, that
will override the pulldown that lets you choose AM or PM.
If you are smuggling or night fishing, you might want a midnight tide,
so you might specify an Earliest time of 11PM and a Latest time of 2AM.
TideFinder will check the times and compare accordingly.
TideFinder only looks at tides in the specified time period.
Tide Higher Than and Tide Lower Than
There are a number of different ways to search for tides:
Specify Tide Higher Than and only tides higher than that height
in feet are found.
Specify Tide Lower Than and only tides lower than that height in
feet are found.
Specify Tide Higher Than with a value smaller than that for Tide
lower Than and only tides between those two heights in feet are found.
Specify Tide Lower Than with a value smaller than that for Tide
Higher
Than and only tides that are not between those two heights in feet are
found.
The Shortest Tide
The Shortest Tide is in hours and minutes separated by a colon or
period. If there is no colon or period, that number of hours is assumed.
Only tides that meet the Tide Higher Than and Tide Lower Than criteria
for at least the specified Shortest Tide duration are found. Since
TideFinder checks tides every 15 minutes, this is typically set
to one hour. So, to see if you can take your Dungeness Spit hike, you
might see if the tide is below 1 foot for at least 1 hour when you will
be near the lighthouse. Alternatively, you could check for a 4 hour
interval during which the tide is below, let us say 3 feet.
Search
Press the search button to start the search.
Results Formats
There are three ways to view the results of a TideFinder search.
1) TideFinder produces a list of the tides it has found. It gives the
starting date, time and height and the ending date, time and height.
2) It gives a scrollable monthly
calendar with the appropriate days marked in red. Since TideFinder
currently lacks a way of specifying a weekend and holiday search, this
makes it easier for you to check for such tides.
3) If you are wondering why you can't seem to find the tides you want,
or the tides are not when you expected, check the Tide Graph which will
show you the day by day tide curve.
