Marine Insurance is only for goods that are being transported via sea through ships and other vessels. Cargo insurance provides for damages to products in transit via land, sea or air.
The main difference between Marine Insurance and Cargo Insurance is that marine insurance covers a lot of benefits, and the insured party gets an option to choose from the subtypes. In contrast, cargo insurance just covers the losses that are caused due to timing delay of the ship or an accident as it is only a subtype of marine insurance.
Marine and cargo insurance are both essential for the protection of goods during international trade, but marine coverages encompass a lot of other aspects as well.