If you have a transit visa, you can stop in Belgium en route to another country in order to switch aircraft or ships. Transit visas come in two different varieties:
Visa for airport transit: While you wait for your next flight, you are permitted to stay in the airport's international terminal in Belgium with this visa. Transit Permit for Seafarers : A transit Schengen visa for sailors is a type of visa that enables you to dock your ship temporarily in a Schengen seaport. Even if you have to spend the night in Belgium, you cannot leave the Schengen seaport.
Documents you need before you apply for Transit Visa Belgium are listed down below
Required documents to apply for Airport Transit Visa
Process - Transit Visa Belgium online
Process- Transit Visa Belgium