@txmsails - bowthrusters draw a lot of electric power, a larger boat will have a 16HP motor that draws around 12,000 watts. At 24V that is a whopping 500 amps. Not only does the motor heat up, but so do the batteries and cables producing and carrying that load.

My bowthruster is relatively deep and far back. I singlehand and use it for fine adjustments when approaching a mooring, as the rudder has no effect when I'm that slow. That allows me to easily pick up moorings alone without any stress. I also use the bowthruster when leaving a mooring or anchoring spot in tight conditions. Even at low speed it makes my turn radius much, much smaller.

I use 1-2 second bursts, that is enough to move my bow 10-20 degrees. When I dock I prefer to back in. I will line the boat up and center the wheel while about a boat length away and use 1-2 second bowthruster bursts to steer. Sometimes with a strong breeze I'll need to move the bow against the wind and that will entail 5 or more seconds. All of that is well within the design specifications.

The longest I've used one was several bursts of 10-15 seconds over a couple of minutes (I was waiting in the channel at the St. Martin drawbridge and a boat ahead of me had stopped and the boat behind me was too close, and the wind was blowing me towards the rocks) and it stopped working, it was a thermal fuse as it later worked again when I'd anchored and wanted to fix the problem.