Things that could be improved on from a basic system.

Consider using: STM32L, or WL, module with lora, nrf52 or 54 if available.

• Avoiding DoS.
• Spam / abuse.
• Forward secrecy.
• Key management / IDs.
• Privacy / anonymity / pseudanonymity. Cruisers may not always want to be trackable.

• Emergency messages, priority, QoS.
• TX power management.
• Integration also with wifi mesh, APRS, Amateur packet radio, …
• Use of LoraWAN where TTN or similar is available, but no other useful mesh nodes.

• Antennas, filters, and amplifiers optimised for use near masts and other radio equipment. Immunity to close VHF transmissions, and high power HF.
• Low noise switching power supplies, e.g. for use beside VHF / AIS, HF, MF (Navtex) and even LF (Radio 4) antennas.

• Development of wind, air, maybe water too.