FAQ

Here are the answers to some of the questions users have been asking. Tap on the questions to reveal the answers...

• What is an MMSI and do I need one to use SeaNav?

  You do not need an MMSI to see and be seen on SeaNav.

  Maritime Mobile Service Identity (MMSI) is a series of nine digits which are sent in digital form over a radio frequency channel in order to uniquely identify ships, coast stations and Navigation Aids.

  If you have an MMSI or obtain one you will be able to use SeaNavs' advanced features to share your location and be seen on other Global AIS systems maps like AIS Hub, Marine Traffic and ShipFinder etc.

  Having a MMSI assigned in SeaNav also allows you to upload gpx waypoint overlays to your map - email the gpx file to yourself. You can also view your current track on google maps by browsing to http://boatbeaconapp.com/go/mmsi where mmsi is your mmsi number.

  In the US you can obtain a MMSI in minutes by visiting the USCG approved agent and using their online form. We can provide you with a free SeaNav MMSI, email us at support@pocketmariner.com. In the UK visit Ofcom MMSI

  Please note that the SeaNav MMSI numbers are not official MMSI numbers and are only used for position reporting at MarineTraffic.com and other internet based AIS systems like SeaNav. This number is NOT to be programmed into any radio equipment such as AIS transponders or DSC radio.

• Does SeaNav work in the background?

  SeaNav works in the background when you are in 'On My Boat' mode — tap the sailboat symbol at the bottom left to enable it. When active, it continues transmitting your position and running Collision Detection, Anchor Alarm, and Theft Alarm even when you switch to another app.

  Collision Detection sounds an alarm once every 5 minutes when a potential collision is detected. The app icon shows 111 if a CPA alarm has fired.

  To stop SeaNav using power in the background, tap the sailboat icon again to switch 'On My Boat' mode off (greyed out).

  Note: background mode keeps the Android GPS active and uses more battery — expect around 4 hours on a full charge.

• How do I stop SeaNav running in the Background?

  To stop SeaNav running in the background, tap the sailboat icon at the bottom left to turn off transmit and collision detection. When the icon is off (greyed out), SeaNav will not run in the background or use GPS power when you switch to another app.

• How do I enable Collision detection?

  Tap the (i) button at bottom left of screen to open Settings, and set Collision Detection on. Boats that are going to be within 200m of your position in the next 10 minutes will start flashing on the screen and sound an alarm. If you tap on one ofthem it will show the Closest Point of Approach (CPA) distance and eta.Collision Detection also works in background mode.

• How real time is SeaNav?

  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.

  SeaNav receives data from a collection of different sources. All the data is timestamped.

  Around 80% 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 realtime feeds on this map Global 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. A boat travelling at 30 Knots would have a placement error of +/- 200 meters.

  SeaNav interpolates the positions between updates.

• How do I upload/attach a boat photo to its information page?

  Please send us a copy of your photo and your Boats MMSI number to support@pocketmariner.com. and we will add it to our service for you.

• 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.

• Searching for places isn't working?

  Please try re-booting your device (battery pull). Apparently the Google Geocode service that we use to search for places requires a re-boot of the device to work correctly after a recent OS upgrade.

• "I see no ships"?

  SeaNav shows all other SeaNav boats on its maps. To show boats that are not using SeaNav it uses ship data provided by a network of shore based AIS receiving stations. The best coverage (over three fold increase) is enabled if you have AIS sharing on. You can check the coverage for your area on SeaNav or via this web site Total coverage

  We have 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 help@pocketmariner.com , especially if you would like to share your AIS data with us to improve coverage.

  One other possibility is the app is not authorised - check the item about "...un-authorised.." below if you see the app not authorised message

• How do I get the screen to rotate with the compass?

  There is an option in Settings — Rotate Map with compass — to enable map rotation.

• How much data does it use?

  SeaNav only uses mobile data continuously for internet AIS. 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.

• Sharing AIS Data

  SeaNav relies on data from AIS base stations all over the world. Sharing with us is easy. If you have an AIS base station and want to see your data on SeaNav please contact us as at help@pocketmariner.com and we'll send you simple instructions on how to do this.

• How do I turn the gps information on and off?

  GPS info is displayed at the top of the screen when you are in Compass and Transmit mode. It displays your current longitude, latitude, heading, map scale (from the centre to the compass red ring), Course (cog) and Speed (sog)

  N.B. When GPS data is showing the Android GPS system is active and will use more battery power while the app is running.

• Does SeaNav work offline without an internet connection?

  SeaNav charts and routes work fully offline without an internet connection. AIS ship tracking requires a data connection to receive and transmit position information. Cellular data coverage typically extends over 12 miles offshore in popular coastal areas, so a connection is usually available when you need live AIS.

• Calibration

  If your compass reading is wrong try re-calibrating it by rotating the phone a few times in each axis and then 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 Android earbuds. The compass may need to be calibrated from time to time.

• Support for VGA/TV out e.g. for MFD's

  Many modern Android devices support screen mirroring or video output via HDMI, USB-C, or wireless casting, which can be used to display SeaNav on an MFD or external screen. Check your device's specifications for video output capability.

• "...this application is unauthorised..."

  This is a Google Play store issue and should be able to be corrected by checking the following. There may be something here which should fix the problem: Thanks for your email and sorry to hear you are having problems with the Play Store. This is a general play store error that occasionally affects purchased apps. There are two suggested solutions on the web

  1. Try clearing data AND cache for Google Play, reboot, and then try again. Settings>Applications>All>Google Play>Clear Data and clear cache.
  2. Settings > Application Manager > All > Locate Download Manager (will be at the the bottom of the list when it's disabled) and make sure it is enabled.

  If these two don't sort things out try the following:-

  1. Ensure your WiFi connection is stable
  2. Uninstall SeaNav
  3. Close all applications
  4. Reboot your device
  5. Ensure you are logged in using a valid g-mail account. We have had reports from other players that using a "googlemail.com" e-mail account was the problem, which was corrected after switching to "gmail.com"
  6. Check to see that you have approx. 2 GB of free internal storage space
  7. Clear your cache
  8. Re-download/install the app.
  9. Remain connected to the internet while starting the app and still logged in to your valid g-mail account. (must be @gmail.com not googlemail.com)

  Please note that uninstalling the app will erase your current boat data. If you have already set this up before experiencing this issue and do not wish to lose your saved data, please try the rest of the steps without uninstalling/re-installing.

  If you're still having trouble, please contact with the following information so that we may investigate the problem for your device:

  1. Confirm the model of device which you are using.
  2. What version of Android is installed on your device?
  3. Is your device rooted?
  4. How are you connected to the internet?
  5. Where you download SeaNav from?

• Navigation Safety?

  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 Android 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.

• What countries are SeaNav charts available for?

  SeaNav charts are available for the US, Canada, UK, Ireland, France, Germany, Spain, Portugal, Denmark, Norway, Sweden, Italy, Australia, the British Virgin Islands, and Bermuda.

• Does SeaNav support NMEA instruments?

  SeaNav supports NMEA 0183 instruments via Wi-Fi or USB. It reads depth, wind speed and direction, water temperature, GPS position, speed, and AIS data from onboard transponders.

• What is the difference between SeaNav and Boat Beacon?

  SeaNav provides fully interactive vector marine charts for 15 countries, with support for routes, waypoints and points of interest. Boat Beacon only includes raster charts for the US and UK. SeaNav is the more fully-featured option for international sailing and passage planning.

• How does SeaNav compare to other marine navigation apps?

  SeaNav combines official charts, live AIS ship tracking, weather forecasts, tide data, and advanced route planning in one affordable app. It offers professional-grade features comparable to Navionics Boating and SavvyNavvy but at a more affordable price. SeaNav is developed by PocketMarnier Ltd and is available on Android and iOS.

• Is SeaNav suitable for coastal and offshore passage planning?

  SeaNav is suitable for coastal passage planning. It includes route planning with waypoints, live AIS ship tracking, weather forecasts and tide information. Charts are available for 15 countries across Europe, North America and Australia. For offshore passages, SeaNav is best used alongside other safety equipment and sound seamanship practices.

• How much does SeaNav cost?

  SeaNav is free to download and includes demo charts for popular areas. Full marine charts for each country require a yearly subscription. Pricing varies by region — visit SeaNav on Google Play to see the current price in your area.

• 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 help@pocketmariner.com. We'll do our best to get back to you quickly!

We hope this helps you enjoy SeaNav!