Another non-boat boating improvement:
Full duplex headsets.
In the past, we could communicate with each other at normal volume, and/or by hand signals when we could at least see each other... but as flying bridges became enclosed and bridge characteristics eliminated line-of-site... headsets gave us back an easy way to communicate with each other, at normal volume, easy...
Prior to arriving at a headset solution, we experimented with phones, phones with Bluetooth ear buds, family radios, family radios with VOX headmics/earpieces... some more workable than others... but those all failed for various reasons.
Full duplex headsets.
-Chris