We thought the following explanation about SafeTrx was worth sharing,
A pleasure to talk to you earlier. As discussed the best use of SafeTrx by your friends on their Durban to Cape Town rowing voyage (with no onboard power source for charging a phone) would be to use the 30 minute interval in Track Only mode, to maximise battery. See screenshots below showing how to select that mode and where to adjust the tracking interval.
As mentioned, we had a tracked event over a 50 NM course from the Scilly Islands to the UK mainland in which a paddler tracked in this manner for over 7 hours. To see her progress click on https://flotilla.safetrxapp.com/events/oceansportuk/cc2018 and select Marie Buchanan. Her position, speed and bearing at 30 min intervals were available to CG if she had a need to press the Emergency button.
To hear the event organiser talk about the value of SafeTrx for the event you could watch the video at https://www.facebook.com/SafeTrx/videos/2092057297489214/
Also, we would suggest following steps:
- Make sure phone(s) are fully charged.
- If you can, use a backup battery bank and attach it to the phone to extend the battery life.
- For iPhone use the new Apple iOS feature to check the max capacity of the iPhone.
- Make sure all other data logging applications (such as Strava etc.) are deactivated.
- Make sure the phone has a clear and unobstructed view of the sky and land before beginning. This will allow the phone to get a lock on the GNSS satellites and the nearest cell tower.
- The phone should be in the chest area in a waterproof plastic pouch.
- Do not put another electronic tracker in the same waterproof pouch.
- Turn down brightness on the device.
- Switch off WiFi and Bluetooth.
The NSRI SafeTrx app does requires an internet (i.e. mobile data) connection to transmit location data in real time, and to start/stop trip recording. Where the SafeTrx app experiences loss of internet coverage, it stores the trip location points on the Smartphone. Once an internet signal becomes available again, it sends the backlog of stored trip information to the server and resumes posting trip information in real time.
If you enter a passage plan using Sail Plan mode and lose coverage, SafeTrx will send a SMS to your emergency contacts when the ETA has exceeded, and another SMS 15 minutes afterwards. The emergency contact should then try to make contact with you. If you are arriving into an area of poor internet coverage, it’s best to advise your emergency contact of this before making the trip or send them a SMS when you arrive safely. The emergency contact will need to raise the alarm if they deem it necessary. If loss of coverage does occur and your trip is overdue, the Coastguard can be contacted over VHF or phone so that you can advise them that you have arrived safely. It’s worth noting that while a network data connection may be unavailable, you may well be able to use the phone and send a SMS.
If you are concerned about poor mobile data coverage in the area that you intend to use the NSRI SafeTrx app, it would be advisable to use the ‘Track Only’ option as this will not alert your emergency contacts if you are overdue. There is also a handy sharing option available in both Sail Plan and Track Only modes. Once you have started a trip on either mode, there is a share icon at the bottom of the screen that allows you to share a link to a live map that’s tracking your location. This can be shared via SMS, e-mail or a social media channel of your choice from the app. The NSRI SafeTrx webpage with your location information is accessible to anyone that has the URL. If your friends and family share the URL (without your permission) their receivers can also see your location or trip. When you close the trip, the app no longer shares a location and the live map advises that the trip has ended.
Best regards and I hope the trip is a great success.