TotalTide Review

August 15th, 2004 by JCB
Posted in Book Reviews | No Comments »

TOTALTIDE Review

With the requirement for a pilot to produce a passage plan now more or less mandatory

anything that can make the task easier is to be welcomed. For example in London we

have four main approach channels and the majority of ships are restricted by their draft

at some stage of their passage so a computer tidal program to save thumbing through

printed hourly predictions and interpolating times and levels has obvious appeal! Some

districts have set up specialist passage planning programs to run on a laptop or handheld

unit (I’m hoping to review a couple of these in the future) but these “custom” units

represent a major investment since they have to be specifically tailored to the pilotage

district.

Having seen TotalTide program running on several ships I have obtained a review

copy from the UKHO in order to establish whether or not it could be a useful, passage

planning tool for pilots. The immediate answer is that in its present format with

comprehensive tidal heights and streams it has potential but in my opinion is somewhat

frustrating in that although all the information necessary to create a pilotage passage

plan seems to be contained within the program it cannot easily be used for that purpose.

 

The product

The program is provided on a single CD Rom which will only run on the MS Windows operating system although the UKHO inform me that it will run on later versions of the “MAC” fitted with Windows compatibility.

With the tidal data protected by Crown Copyright The UKHO are understandably paranoid about piracy and the (too long) access code provided with the program needs to be supplemented by a permanent key code obtained by registration either by email or post. Once the permanent key code is entered the use of the program is limited to two computers and each one requires its own permanent key, however, the UKHO are currently working on an edition which will be able to run on networked computers. Once the permanent key is obtained the program use is unlimited but updates for additional ports can be obtained annually for an extra charge.

The display

Once the program is running the screen consists of a chart of the world along with two sub windows: List and Filter The “List” provides a list of all the ports and streams purchased The “Filter” provides configurable data for selected use from the list of ports and streams.

The whole display can be configured with open data panels to individual user requirements.

The chart display

Upon opening, the display default is for tidal stream data using the current date / time from the computer’s clock so in common with all time based programs if your computer clock is incorrectly set then the data displayed will be rubbish! Once the program is running the time zone required by the operator can easily be chosen and set. Scrolling the chart is the easiest way to navigate around the various areas / ports and there are various ways of panning and zooming around the display. If data is required for a port whose location is not known then typing in the port’s name or part of it in the search box will highlight the port on the list if it is in the database. Right clicking on the port will provide an option for that port to be centred on the chart.  This basic display is suitable for most usage since upon zooming in on the chart, local “standard” and “Secondary” ports and other tidal data points are displayed and clicking on these brings up an additional data window. However in the interests of research (I do suffer for my readership!) I decided to customise a “Filter” for the Thames Estuary. One word sums up this exercise and that is: perverse!! Wishing just to produce a display for the Thames Estuary with a dozen or so tidal data centres involved working through the whole list of areas and ports right clicking on hundreds to exclude the data points not required in order to select those that were!! Why on earth a simple select system of just clicking on the data points required is not used totally defies logic! There also doesn’t appear to be any facility to edit this filter data once it has been saved without creating a new list.

The tidal data

Zooming in on the chart display firstly brings up the standard ports then the secondary ports and tidal streams for an area.  Further zooming brings up additional data for the ports providing information as to whether the tide is flooding or ebbing plus the time and height of the next high or low water. The tidal streams have a tag displaying the direction and rate of the tide.  The time / date for a tidal calculation can be changed by various means but I found them all rather fiddly. In my opinion, a simple request box for entering the required date and time would be more user friendly!

However, once the default or input time and date is selected additional information is easily acquired. Double clicking on either port or stream data brings up a window containing much useful supplementary data.

Tidal streams

The additional data on the tidal stream “diamonds” is a table of direction and rate as found on a normal chart along with detailed tables of predicted future data which can be set for intervals between 5 minutes and 1 hour.

Ports: This is where this program is of value to pilots and includes standard and secondary ports along with data reference locations such as buoys and structures. Double clicking on one of these “ports” brings up a wealth of data but of particular interest to pilots are the tidal curve graph and vessel UKC features. The “graph” tab brings up tidal curves for an adjustable period around the date / time selected and a cursor can be run along the curve to either provide the time a certain level will be available / lost or the level predicted at a certain time.

The “local” tab permits the user to enter data critical data for that port such as a ruling depth and bridge height. Once this data has been set the “clearance” tab enables the user to enter a vessel’s draught, under keel clearance and air draught and once these have been entered the graph function will produce a line across the graph showing the “minimum safe height” for navigating that vessel. It is then a simple matter to locate the cursor over the intersection of this line on the graph to obtain the tide available and lost times.

Sounds good! – Where’s the problem?

The “clearance” function is good as far as it goes but what I found frustrating is that there is a vast amount of information contained within this program and although I have no technical knowledge of how the program works I feel sure that with a fairly simple program upgrade the data could be used to provide a comprehensive passage planning programme, not just for pilots but for all users. How? My suggestions would be as follows:

Tidal target points: There is a facility for users to create a “custom” port in any location but this requires input of harmonic constants and such data is not readily available to the average user.  Critical depth points often lie between two tidal data points on the chart and mariners currently interpolate between these points. The predictions in this program will be based on the co-tidal curves for an area and so surely it should be possible for a user to enter the Latitude and Longitude of a “target” spot and have the program undertake the interpolation between the nearest data reference points in the same manner as we do manually and the UKHO have confirmed that they are looking at this facility. If such a facility were added a simple table facility could possibly be added which would enable a user to enter several such target points along with the ETA at each one to provide UKC data for a passage. There should also be a facility to save plans with an edit facility should the critical depths change.

Tidal surge compensation: The program provides standard predictions but for planning it should be possible to manually enter anticipated tidal variations and thus amend the standard predictions prior to a passage being undertaken. 

Clearances: The current clearances facility permits a vessel’s draft and UKC paramenters to be entered. Once this is done the data page displays the UKC for the time when the data is entered. This is pretty useless. Why not display the available and lost times on this page which would remove the necessity to switch to the graph page to read them off by means of the cursor?

Conclusions I am not a computer expert so am not sure how complex such additions to the program would be. However, many dedicated passage planning programs use the data provided by the UKHO for tidal calculations so it would seem logical to me that the UKHO should be able to utilise their own data in such a manner!  I therefore get the impression that this program has comprehensively and successfully converted the data from their printed tide tables into a computer program but in limiting itself to that function it has, in my opinion, missed an opportunity to produce a really useful tool to bridge the gap between basic tidal data and a full electronic chart with tidal planning facilities.  However, upon raising this point with the UKHO they have confirmed that they are currently working on a program that can be integrated into other navigational programs so watch this space! My verdict 7/10 (with great potential). TotalTide. Each area (e.g. NW Europe) costs £70. Annual updates cost £56. Available from chart agents and cannot be purchased

directly from the UKHO. (Pilots purchasing this program may be able to offset the cost against tax.) Weblink: http://www.ukho.gov.uk/total_tide.html   JCB