Why short-sea shipping?

Short-sea shipping is restricted to European seas and concerns shipment to, amongst others, England, Scandinavia (Norway, Sweden, Finland and Denmark), Ireland, Russia, Spain and Portugal. Within Europe, transporting is often done by short-sea shipping (almost 50%). Dry and wet bulk, like fertilizer and petrol products, and conventional general cargo like wood and paper are usually transported in this manner. Semi-finished and finished products could also be transported by short sea. Yet, this is mostly not what really happens, while in fact it could certainly be a good alternative to road transport.