Hi Hertzie,
I'm almost finished doing a GSL addition for Zeebrugge. As B24Guy says, you can place Allen's mole in a mission. The trouble with placing it in every mission where Zeebrugge is needed is that there will be slight variations in the mole placement. At present the Belgian coast in CFS2, even with Sander's European coastline, has promontories on the coast at Zeebrugge and the canal is "blocked" in places.
Fortunately Kevin Driver has come to my rescue by redrawing the coastline as it was before the modern port was created. Kevin has also opened the mouth of the port. The mole can be placed using the GSL file, also made by Kevin. With those files everyone will be seeing the same Zeebrugge mole. Placing the mole as a separate GSL add-on also has the advantage that objects can be placed on and around the mole, and in the town, representing different stages during both world wars. My focus is on the period 1917-1918.
I'm still looking for a couple of objects. A large grand hotel in the late 19th century European style, a cover/awning for submarines which can be placed on the mole and on the dock inside the port and a representation of the lock gates for the canal. At present I am using the sluicegate object for the lock which is really too big for this canal as it has a huge area of concrete structure around it. The search continues.....