Most cable laying ships are in 10,000 tonne size , ships this size use typically 50 tones of fuel a day at cruse speeds , cable ships travel much slower than that. The fuels ship typically use is one of the dirtiest as compared to RP-1 kerosene a falcon 9 uses. I am not so sure rockets are not cleaner approach.
On the downside The life of a cable is 20 years or more , as compared to only 5 years of a starlink sat . Definitely lot more data can go through a cable , it is not apples to apples comparison .
On the downside The life of a cable is 20 years or more , as compared to only 5 years of a starlink sat . Definitely lot more data can go through a cable , it is not apples to apples comparison .