SeaNav FAQ - iPhone and iPad

Here are the answers to some of the questions users have been asking. Tap on a question to show the answer...

• Are the charts updated and how do I get chart updates?

  We release updates to the charts on a quarterly basis and SeaNav regularly (once a week) checks to see if there are updates available.

  You can force SeaNav to check for updates immediately by force-quitting SeaNav and re-launching it to get it to fetch the new Catalogue and check for chart updates. Follow these instructions to force quit SeaNav:-

  
  1. Double click the home button.
  2. Slide the apps from side to side to find the one you want to quit
  3. When you find it, simply swipe up the screen as if you're moving the app from the bottom of the screen to the top. The app will disappear and it has been quit.
  4. Click the home button again to return to using your iPhone.
  5. Re-launch SeaNav. It will fetch the latest Catalogue and Charts. If you have a lot of charts already downloaded and many of them have updates it can take a bit of time to refresh them all, so this is best done when you are connected to a good internet connection and not in a hurry!

• Auto-renewing In App Purchase (IAP) subscriptions

  All our in-app purchases are 1 year subscriptions, which automatically renew at the end of the subscription period unless auto-renew is turned off at least 24-hours before the end of the current period. Payment will be charged to your iTunes Account at confirmation of purchase, and will be charged for renewal within 24-hours prior to the end of the current period. Subscriptions may be managed by the iTunes account holder and auto-renewal may be turned off by going to Account Settings after purchase or from within SeaNav via settings/SeaNav Chart Store/Manage Subscriptions. No cancellation of the current subscription is allowed during active subscription period.

  Should you cancel or not renew a chart subscription you will still be able to see the charts updated to the expiry date of the subscription. For instance, if you delete and re-install the app or migrate the app to another device you will still be able to obtain the charts updated up to the expiry date of your last subscription period.

  You can purchase more charts and manage chart subscriptions from SeaNav's Settings/Charts and Add-ons

• Will SeaNav work if I don't have an internet connetion?

  Yes. SeaNav only requires a data connection to download new charts or to receive live ship , tide or weather information. Once downloaded the charts are stored in the app so you can use the app to help navigate even when you are offline and out of reach of the internet.

  You can also download Tide tables for any period upto a year ahead and store those in your Calendar app as iCalendar events.

• Does SeaNav work in the background?

  Yes, if you are "Sailing" - have the Sail Boat Symbol, bottom left, selected - SeaNav will continue to update your position and track and alarm waypoints even when you leave the app.

  If you want SeaNav to stop and not use any power when you close the app or switch to another app make sure the "On my Boat" symbol is off - greyed out.

  N.B. When navigation is enabled the iPhone GPS system is active and will use more battery power while the app is running even in background. It will last upto 4 hours on a full battery charge.

• How do I stop SeaNav running in the Background?

  Tap the sailboat icon at the bottom left to turn navigation on and off. When on - it will also run in background - when off it won't.

• Can I add favourite locations?

  Yes, use the Favourite Places/Points of Interest (POI) feature. Just tap anywhere on the chart where you want to add a location and select "Add POI here". You can drag the marker around, change it to one of 7 different types and add a name and information.

  Add markers for places you want to remember or share with friends and add a photo too. There are several types available;

  • fishing spots
  • bridges
  • diving locations
  • favourite anchorage spots
  • hazards
  • race markers for club racing
  • favourite place

  You can also share these via email, dropbox or the SeaNav community by tapping the Manage POIs tab at the bottom of the Routes, Tracks and POI control popup at the bottom of the screen (zig-zag line). You can import POIs and also export all your POIs in one go on the manage POIs view.

  If you share your POIs with the SeaNav community they can be viewed and downloaded on our POI web page.

  POIs can be added to Routes and Routes and Waypoints can also be used to add location that you want to visit or remember. There is a useful guide here that takes you through step by step on how to add routes and Waypoints in SeaNav.

  Favourites and Routes .

• How do I see Ships in SeaNav? How do I get Collision detection?

  SeaNav gets its Ship AIS data from our companion app Boat Beacon .

  Boat Beacon also provides Collision Avoidance and alarms. If you already have BoatBeacon installed you will also be able to see live ships overlayed on the SeaNav Chart.

  If you don't, just get Boat Beacon from the iTunes store to get Live Ship display in SeaNav and real time collision avoidance and alarms.

  You can quickly switch back and forth between SeaNav and Boat Beacon screens using the app icon on the left hand side of the screen; for instance to set Boat Beacon active in the background when you start navigating in SeaNav.

• Tidal Streams?

  You can view the current and predicted tidal flow rates and directions live on SeaNav’s UK and IE vector charts. See Using tidal streams in SeaNav for more information.

• The buoys and ships are too small to see!

  You can magnify the view to any size you want. Double tap with three fingers to magnify and again to return to normal. You can pan by dragging 3 fingers and change the magnification level by double tapping with three fingers and dragging.

  Make sure you have enabled the iPhone or iPad Screen Zoom function in the phone Settings/General/Accessibility/Zoom for this to work.

• How real time is SeaNav?

  SeaNav receives data from a collection of different sources. The GPS fix is updated every 2s and comes directly via the satellites. Ship AIS data comes via the internet and is timestamped.

  The majority of the AIS data is fed directly as it is received by the shore stations and typically there is less than a 1 second delay between the ship sending the transmission and it being available to SeaNav via the internet. You can check which areas have direct feeds on this map Direct coverage

  The other stations report once a minute, they accumulate the data over a minute and then send it to us. So on average these reports are 30s behind real time.

  The AIS standard has different reporting times. Boats at anchor and travelling at less than 3 knots only report their position every 3 minutes. Ships moving at over 23 Knots send updates every 2s.

  A boat travelling at 30 Knots would have a placement error of about 14 meters after 2s and 200m after 30s.

  SeaNav interpolates the positions between updates to improve the placement for boats on a slow refresh rate.

• How do I get my latitude and longitude?

  Just tap on your boat symbol when navigating and it will display your current Lat and Long.

• Can I add my own waypoints and tracks?

  Yes, that's at the core of SeaNav! Tap the Route icon in the middle bottom of the screen to add new routes or edit existing ones.

• How old is the Chart data? How do I update the charts?

  Yes, we get the latest updates from the NOAA and the UKHO and roll these out 4 times a year. You will get any updates automatically when you view a chart.

  The US chart updates are free for life.

  For the UK and Ireland the UKHO license restricts updates to 12 months at a time. If you want to extend this there is an in app purchase option to extend this for further 12 month periods.

• What other areas do you cover?

  We currently have vector charts for the US, CA, UK, IE, FR, NL, BE, ES, NO, HR (Croatia) and DE. We have raster charts for NZ, FI and EE. We will be rolling out Australia, Italy and the Caribbean as soon as we can obtain the chart licenses. If you want us to cover your area please let us know, the more votes the more chance we will prioritise it.

• How do I use zoom?

  Use your fingers to pinch in and out. Tap the compass icon to toggle pan mode which lets you pan around.

• "I see no ships"?

  SeaNav shows all the ships and Boats Boat Beacon can see. Boat Beacon uses ship data provided by a network of shore based AIS receiving stations. You can check the coverage for your area with our free BoatWatch app.

  We have global coverage for most of the popular coastal areas and coverage is constantly increasing. If your area isn't covered, please let us know by emailing boatbeacon@electricpocket.com , especially if you would like to share your AIS data with us to improve coverage.

• How much data does it use?

  The app only uses data if you have the Ships layer or the NOAA Weather buouys layer on. The data rate is low - it depends to a certain extent on how many boats are in view and how much you change the map position/scale. On average it receives about 3 kbytes and sends about 1/2 kbyte every minute. Although it's a pretty low data rate (500bps) it can mount up if left on continuously. e.g. if left on continuously for a 6 hour trip that would be just over 1 Mbyte of data.

  If you are worried about the cost of mobile data when travelling abroad you can normally get deals at around $3 for 30Mb per day or $5 for 70MB per week using a local PAYG sim.

• I want the compass to show True North readings rather than Magnetic?

  Go to Advanced Settings and set the "True North" switch as you require. The label shows the current magnetic variation for your locale in brackets (e.g. (2W)). All bearings as well as the compass display are automatically adjusted to the new setting. When True North is set on the compass and bearing readings will show a N after the number.

  N.B. Using True North requires the iPhone GPS system to be powered up and will consume more battery power.

• Will SeaNav work on an iPad?

  Yes. With a GPS enabled iPad you can navigate in real time.

  If it is a WiFi only iPad you can use a Bluetooth GPS dongle - we recommend and have tested the Garmin GLO. You can also use local GPS via Wifi or GPS from your iPhone with the GPS2IP app.

• Can I take a picture? How do I share my position?

  Use the share button at the bottom right of the toolbar. You can share via email, twitter, facebook and also print and save a photo to the camera roll.

• Calibration

  When using the compass you may see the message, "Move away from any interference, or re-calibrate by waving in a figure 8 motion."

  The built-in digital compass works just like a magnetic-needle compass. The accuracy of digital compass headings can be affected by magnetic or other environmental interference, including interference caused by proximity to the magnets contained in the iPhone earbuds. The compass may need to be calibrated from time to time. When the device displays the calibration alert, rotate the device in a figure 8 motion until the calibration screen disappears.

  See iPhone Compass Calibration for additional information.

• How do I show Lat and Long in Degrees, Minutes, Seconds?

  On SeaNav v 4.4 and later there is an option in Advanced Settings to change the location display between Degrees and Decimal Minutes ( DDD MMM.mmm - the default) and Degrees, Minutes and Seconds (DDD MM SS.ss)

• NOAA CHART NOTICES:

  US marine charts are derived from the official NOAA ENC® vector chart data.

• UKHO CHART NOTICES:

  This product has been derived in part from material obtained from the UK Hydrographic Office with the permission of the UK Hydrographic Office, Her Majesty’s Stationery Office.” “© British Crown Copyright, [2012]. All rights reserved.

  ES charts: This product has been derived in part from material obtained from the Instituto Hidrográfico de la Marina and the UK Hydrographic Office with their permission. ©Instituto Hidrográfico de la Marina 2017,All rights reserved.

  The UK Hydrographic Office (UKHO) and its licensors make no warranties or representations, express or implied, with respect to this product. The UKHO and its licensors have not verified the information within this product or quality assured it.

• Canadian Charts and License

  This product has been produced by Electric Pocket based on Canadian Hydrographic Service (CHS) data, following any minimum standards guidelines that may have been established by CHS, pursuant to CHS Digital Value-Added Reseller Agreement No. 2024-0305-1260-EP. The incorporation of data sourced from CHS in this product shall not be construed as constituting an endorsement by CHS of this product. This product does not meet the the requirements of the Navigation Safety Regulations, 2020 under the Canada Shipping Act, 2001. Charts and publications issued by or on the authority of CHS must be used to meet the requirements of those regulations.

• New Zealand Charts and License

  Contains data sourced from the LINZ Data Service licensed for reuse under CC BY 4.0. NOT FOR NAVIGATION.

• Finland Charts and License

  Contains data sourced from the Finnish Transport Agency's Hydrographic Office / Liikennevirasto / Trafikverket - NOT FOR NAVIGATION.

• Can I send you feedback and ideas?

  Yes, definitely - we'd love to know what you like (and don't like) about SeaNav - the best way is to send an email directly to seanav@pocketmariner.com. We'll do our best to get back to you quickly!

• Navigation Safety?

  NOT FOR NAVIGATION. This application should only be used for basic navigation assistance. Never rely solely on the digital compass for determining direction, proximity or distance. The user is responsible for the prudent use of information provided by this application and must not use it for direct navigation. The accuracy of digital compass headings can be affected by magnetic or other environmental interference, including interference caused by proximity to the magnets contained in the iPhone ear-buds.
  

  Location-based applications depend on data services. These data services are subject to change and may not be available in all geographic areas, resulting in digital compass headings, directions or location-based information that may be unavailable, inaccurate, or incomplete.

  
  You assume all responsibility and risk for the use of this software. The author assumes no liability for damages arising from use of this program.
  
  

  DO NOT RELY ON THIS APPLICATION FOR DECISIONS THAT CAN RESULT IN HARM TO ANYONE OR ANYTHING.

• EULA, Terms of use, Privacy and support

  EULA

  Terms of use

  Privacy policy

  support@pocketmariner.com. Any questions. We'll do our best to get back to you quickly!

We hope this helps you enjoy SeaNav!