A typical weather download of 150 KB or less will take approximately 12–15 minutes to download into the Offshore App with a strong, 5-bar satellite connection.
When downloading weather data through the Offshore App using an Iridium GO!, the Iridium GO! establishes a data call to connect to the Iridium satellite network.
Please be aware that data call time starts when the Iridium GO! begins dialling, not when the weather data starts downloading. It can take approximately one minute to establish the connection before data begins transferring.
Example download times
The Iridium GO! transfers data at approximately 12 KB per minute with a strong, 5-bar satellite signal.
For example:
A 50 KB download will take approximately 5 minutes.
If you download four forecast models at approximately 50 KB each, the total download will be around 200 KB and may take approximately 20 minutes.
Actual download times can vary depending on the size of your weather download, satellite connection and signal strength.
How does Iridium signal strength affect download speed?
The Iridium GO! displays up to 5 bars of signal strength. Your effective download speed can vary significantly depending on the strength of the Iridium satellite connection.
As a general guide:
5 bars – Full download speed.
4 bars – Approximately 50% of full download speed.
3 bars – Approximately 10% of full download speed.
2 bars or less – The data call may fail to connect, or data may transfer very slowly.
For the fastest and most reliable weather downloads, aim for a strong Iridium signal before starting your download.
How quickly can data call minutes add up?
The time spent establishing the connection and downloading weather data counts towards your data call minutes.
If a typical download takes around 20 minutes and you download updated weather data every 12 hours, you could use approximately 40 minutes of data calls per day.
For a five-day passage, downloading Weather Routing, GRIBs, GMDSS and other weather information regularly could therefore use around 200 minutes of data calls.
For sailors who regularly download weather data while offshore, an Iridium GO! Unlimited Airtime Plan is a cost-effective option and avoids having to closely manage the number of data call minutes used.