ground vehicles
Advantages: price / performance relatively good + low communication consumption
Disadvantages: they can not fight against air units except for air defense tanks can leave map Only by transport helicopters

boats
Advantages: price / performance relatively good + low fuel consumption + can leave the map independently + relatively low communication consumption + have a relatively high weapons range
Disadvantages: They can not defend themselves against air units except for air defense boats. Can not take most of the land bases under fire

Submarines
Advantages: Can only be attacked by submarines + can leave the map independently
Disadvantages: Can only attack sea units

Helicopters and airplanes
Advantages: Can leave the map on its own + Can reach all points of a map + Boats and land vehicles which are not against air units are defenseless against them
Disadvantages: bad Price / performance + high communication consumption + High fuel consumption