Electric motors have one key advantage over a diesel when it comes to blue water cruising: regeneration.
It is common practice to run your diesel motor once or twice a day to "charge up the batteries" while crossing an ocean. The winds are consistent offshore, so you don't need the motor for propulsion, but you do need the motor for power.
Imagine being out on a gorgeous day of sailing and then have to crank on your motor for a few hours. All the peace and tranquility is ruined as your diesel clanks and clunks away, shaking the boat and your eardrums for hours!
Electric motors can not be "run" to make power. Running them actually consumes power! The only way an electric motor will produce power is if you are sailing fast enough that the water passing over the propeller actually causes the propeller to spin. This in turn spins the electric motor and causes the motor to act more as a generator, producing power that is then fed back into your battery bank.
There is no need to tarnish your perfect sailing day with a noisy diesel motor. The propeller is spinning all the time and producing power that keeps all your batteries topped off! In this particular moment, we were sailing along at around 7 to 8 knots and the motor was constantly producing between 6.0 amps and 6.9 amps. That might not sound like much until you recognize the fact that this in in 48V. When this is stepped down to 12V, the amps are multiplied by a factor of 4. This means that 6.0 amps @ 48V becomes 24 amps @ 12V and 6.9 amps @ 48V becomes 27.6 amps @ 12V!
Imagine having a quiet source of power that cranks out 24 amps continuously, day and night! Needless to say, we had no issues with power demands while we crossed the Atlantic in the summer of 2018, all without the need for a noisy diesel motor.