Every other provider will make you pay for these costs. It is your responsibility to make sure you don’t use a satellite connection on a ferry by mistake. There is nothing that Simyo can do to block / prevent this because it is your phone that makes this connection.
Also, they don’t make any money out of this, because they have to pay the money to the company that provides the satellite connection.
Your complaint about the costs should be aimed at that company, not Simyo.
Hi @Johnmarktpl,
Thank you for your message. I took a look at your account and I also see that you connected to the maritime network. The maritime network (or satellite network) is the network your phone switches to when you are at sea. This can happen if you are on a cruise ship or a ferry. Your phone then does not connect to a regular land-based tower, but to a mast on the boat.
When your phone switches to such a mast, you will no longer see ‘Simyo’ or ‘KPN NL’ but, for example, ‘Telenor’ at the top of your screen. We always send you an SMS to let you know that you are on a satellite network and inform you of the associated costs. I see that you received an SMS about this on June 14th. The maritime network falls under zone 4, so different rates apply.
It is important to know that as long as the internet connection on the SIM card is active, there is always a chance of data usage, both intentionally and unintentionally. This can happen, for example, due to updates or apps that remain active in the background. It is possible that there was internet usage before you turned off your internet.
I understand that these costs may have been incurred unintentionally. If you send me a private message with your phone number and personal details, I will see if I can do something for you.
Greetings,
Seren
Every other provider will make you pay for these costs. It is your responsibility to make sure you don’t use a satellite connection on a ferry by mistake. There is nothing that Simyo can do to block / prevent this because it is your phone that makes this connection.
Also, they don’t make any money out of this, because they have to pay the money to the company that provides the satellite connection.
Your complaint about the costs should be aimed at that company, not Simyo.
Obviously you not a software engineer. As this is possible.
If your phone can detect and simyo can send you a message, it's also possible to block this network and ask you; do you want to go ahead with this network? Yes/ no.
For example phone gets blocked at €60,- usage on that same network 
Happy to discuss if interested
Obviously you not a software engineer. As this is possible.
If your phone can detect and simyo can send you a message, it's also possible to block this network and ask you; do you want to go ahead with this network? Yes/ no.
For example phone gets blocked at €60,- usage on that same network
Happy to discuss if interested
Actually, I am. I am an industrial automation expert and have been for over 30 years. And I know from experience that things are not always quite as simple and easy to implement as people think.
But seeing you already got an official response there is no point in discussing this any further.
Hsd
ANOTHER EXAMPLE FOR YOU, MAYBE 30 YEAR OF EXPERIENCE CAN WORK OUT THAT THIS IS POSSIBLE AFTER ALL?
Hallo,
Ik krijg net deze sms: Let op! Je hebt € 48,40 aan kosten voor internet in het buitenland gemaakt. Bij € 60,50 wordt je internet geblokkeerd. Wil je blijven internetten? Sms JA naar 1330. Tip: gebruik WiFi om hoge kosten te voorkomen. Groet, Simyo
This example shows that Simyo sends you a text, warning you that you are about to make roaming costs. They cannot differentiate between a satellite connection and a “normal” roaming connection.
There is no point in arguing further (@Johnmarktpl and @Hsd) as I have already provided a thorough explanation in this topic and responded to your question. Therefore, I will conclude this topic.
suggestions from their respective customers 
OUT OF THIS!!