Passage Planners


Ok so you’ve left your moorings and are about to enjoy a nice sail down the local coast towards your evening destination port some thirty miles away. Everything is going well, nice weather, good sea conditions, nice beam reach, everybody on board is happy.  That is, until you approach that headland about half way through your passage.

During your approach to it, the tide has turned foul and the wind has picked up. Sea conditions have altered from flat calm to quite a swell. The sea area around the headland is looking quite rough and  your boat speed is falling away.

The best solution now is to steer a course to give the headland a wide berth.

 Otherwise you could take the chance and soldier on. Either way you may well come to regret this decision as you battle against the stream, on engine, and with your passengers and crew wishing that you, the skipper, had planned the passage better. Surely you could have calculated the time when the tidal stream was in your favour and not against you? Couldn’t you?


Absolutely, and this is what our Tide & Tidal Stream Event Calculator endeavours to do.

Furthermore - It’s Free to download and use! And it is also unique!
By using the calculator, together with tide tables and the start and end times of the relative flow direction you will be able to calculate the times when the tidal stream is in your favour. This can then be assumed to be a ‘tidal gate’, to be included in your Passage Plan in order for you to adjust the start time of your passage accordingly and in good time to take advantage of that favourable stream. Much better for instance than hanging about off Alderney for 6 hours having to wait for the tide to turn in your favour because you didn’t check the tidal streams when leaving Guernsey!
TScalculate allows you to calculate several expected Tidal Stream Events on the same form, which can then be printed out and attached to your Passage Plan for use in timing your passage. It is a very professional way of detailing your intentions and expectations.


How to Download TScalculate
(Full instructions on its use are included with the calculator).


Click HERE to see a preview of the online TScalculate Instructions (opens in a new window)

Just send us a couple of details as requested below and download your free Tidal & Stream Event Calculator. We only need a few details to record that you have downloaded it. We will only contact you if there is a revision to the calculator.
Please note that a  manual plastic encapsulated version of the form can be purchased here

(page opens in a new window).
Prior to downloading the calculator you will be asked to confirm your acceptance of The Terms of Use of the software.
Please note that by clicking on the following link you will go to a page which will ask for your email address in order to download for free version of an excel sheet which will enable you to use TScalculate free of charge. By clicking on the link you confirm that have read and agreed to our privacy policy and our web access agreement and our online sales terms & conditions  and furthermore agree that you will be using the form for your private and personal and non-commercial use only and at your own risk and that it's owners and/or employees are not responsible for your use or misuse of the downloaded Excel sheet.
Please note that the original download was an Excel application written using Excel 2011. The most recent version (March 2022) is compatible with the current version of Excel for Mac. You will need to have a licensed Excel version on your device to run the application. It should work correctly with any current versions of Excel.
TScalculate is suitable for Microsoft PC and AppleMac computers but is not currently developed for iPad or iPhones. reserves the right to continue to develop this application. The current TScalculate version is TScalc_3 _Ver 1.02.xlsm.
Click on the link below to go to the free download page.
TScalculate - for Tidal Stream calculation