The benefits of electrification he lists include improved hull designs and hull coatings, which could go with any new design, and electric-specific improvements:

Optimal Propeller Design and Conditioning

Ships can reduce fuel usage by 15%-20% by using more efficient propellers and improving the water flow conditions around them.

Large cargo ships almost all use giant two-stroke marine engines because they are efficient and reliable. Another advantage of two-stroke engines is that their slower-than-normal speed means they can directly drive propellers without expensive and complicated gears. That speed and location are not optimal for propeller efficiency, though.

Electric ships can use larger propellers with lower RPMs that are more efficient. They can also place the propellers further outside the wake using propulsion pods because electric motors are tiny compared to marine engines. Many cruise ships already use these because diesel-electric powertrains better match their requirements than direct-drive powertrains.

Fins and other devices can smooth the flow around the pods, further improving propeller efficiency.

Wider Efficiency Curves

The flexibility of electric powertrains can provide another 5%-10% reduction in fuel usage. Engines have a very narrow range where they operate at peak efficiency. In the real world, they rarely run in optimal conditions. Electric motors have good efficiency across a wide range of speeds.

Slow Steaming

Ships usually slow down when fuel costs are high because reducing speed can cut fuel consumption dramatically. A problem for ships with marine diesel engines is that engine efficiency drops precipitously at lower RPMs, resulting in diminishing returns for slow steaming. Electric motors don’t share this issue, so they get the full benefits of slower travel. An electric ship will use ~1/8th of the power and ~1/4th of the energy to complete a trip if it halves its speed. Ship owners gain the ability to load up the batteries and blaze ahead if spot freight prices are high, or they can slow down to extend range and reduce costs if necessary. It is challenging to have both options with traditional cargo ships.

The benefits must be really obvious, because the author didn’t list any.

Also, no mention of recharging time, or who would pay for the grid upgrades to provide megawatts of power, or mention that the ships would be limited only to ports with charging facilities.

Also, packing the batteries in at the density he’s talking about is questionable. LFP batteries burn really good, and hot, and are not extinguished by water, and emit toxic gases when they burn. The propensity for sudden combustion is why it’s recommended they be spaced far enough apart to (maybe) avoid a chain reaction.

The ocean is no place to assume that everything will go to plan.