Close, but not totally correct re cars and marine engines with regulators internal to the alternator. Cars and standard marine engine alternators have what are called "dumb" regulators. There is no float charge. They very rarely sense the battery voltage. They sense the alternator output and this is usually internal to the alt itself. They have a fixed voltage, 14.4 volts in the last few decades, 13.8 previous to that. They will run at their fixed voltage day in and day out with one exception only - the output will drop a bit when they get hot. For example my car is 14.4 cold and after a few hours is 14.2 to 14.25 due to heat build-up. On Yanmar diesels the Hitachi alternators that are standard will reduce the voltage a lot more than this as they get warm, lengthening the charge time greatly, especially if the battery bank is large.
External regulators are rarely seen now unless they are purchased aftermarket. These are 3 or 4 stage regulators and most do sense the battery voltage at the battery post. The better ones like MC-612 and MC-614 from Balmar also have the option of both battery and alternator temperature sensors, a soft start feature, and the ability to dial the output back to say 70% for longer alternator life with batteries with high acceptance rates, usually AGM batteries but it is also a good feature to have with a large bank of flooded batteries.
External regulators are rarely seen now unless they are purchased aftermarket. These are 3 or 4 stage regulators and most do sense the battery voltage at the battery post. The better ones like MC-612 and MC-614 from Balmar also have the option of both battery and alternator temperature sensors, a soft start feature, and the ability to dial the output back to say 70% for longer alternator life with batteries with high acceptance rates, usually AGM batteries but it is also a good feature to have with a large bank of flooded batteries.