Remote monitoring of NMEA Data

I have a MAX BR-1 Mk 2 on my boat. NMEA Data from a weather station is now included on the LAN. What do I need to do to be able to sign in to the Pepwave network from a remote location on the internet and be able to view the NMEA Data?

What weather station? Some have cloud services. Why do you specifically need to view the weather information in NMEA format?

The weather station is an Aimar 220WX. It sends information by cable in NMEA 0183 format. There is no cloud service. I use an NMEA to Wi-Fi adapter in station mode to place the Data on my Pepwave LAN Wi-Fi. I then can use it in a iPhone App that displays it in simulated gauges. I like to be able to do so when remote from the Wi-Fi.

OK establish pepvpn or speedfusion connection then you are on the same LAN?

Since I want to log in to my LAN remotely on my iPhone, I assume I should use L2TP with IPSec. I am confused whether this is a direct connection from phone to router, or whether I need some third party VPN server?