The docks/pier would probably be near the beach, like Boardtrot, I think? Since the town is high up on the cliffs, you’d need to walk down from there to reach it.
All known maps of Maretime Bay have never shown what is located in the south-west and west of the city area and surrounding area. We now know that it is where the beaches with the amusement park are located, where the terrain seemed to slide over into flatter land - there are cliffs and cliffs to the east where the lighthouse was, and to the north where there seemed to be a very short distance between the mountains and the sea . The old Hasbro map from G4 showed that there is swampland and estuaries on the west and south-west shores of Horsehoe Bay, which means it will flatten out to the west, on the ANG it was possible to see that the mountains appeared to be closer from the north, for looking towards Maretime Bay from the height where the lighthouse stood, no higher ground could be seen.
The map itself and the topographic conditions revealed that Maretime Bay had probably existed for a very long time, because Canterlogic is located on an artificial hill which can only be a mound called a motte, usually artificially constructed by piling up turf and soil. This means that there was a very old fortress there. Probably a motte-and-bailey castle as in old England from the 10th century. The old town was located on the underside of the castle, while the center of the town seems to be divided between an older and a newer quarter on either side of the main street. We know that there is a road from Maretime Bay deeper inland, which led to inner Equestria, which runs in a northwesterly direction. And there is probably a road to the west. There were certainly larger and more suitable port towns to the west, so Maretime Bay probably only had local importance in earlier times, possibly for fishing and trade. It was a holiday resort in the olden days, which the town still bears its mark.
But Maretime Bay was also a place of refuge to avoid unpleasant surprises such as pirates. The early castle, the town which was quite high above sea level and the topographical conditions are very similar to those found in many Greek towns which in ancient times were subject to pirate attacks. Maretime Bay was a Kastro. This Greek word refers to medieval fortified sites as a safe place of residence for permanent residents. And such castros do not have harbors. The best example is Athens and Piraeus, which in antiquity was the city’s marina. Many older cities in several countries around the world had their separate harbors, which are sometimes far away.
This basically means that there is a port location near the theme park - and we haven’t seen it. There are piers and boats there in the theme park area. After all, hundreds of tons of steel, wood, food, and so much more have to be shipped into Maretime Bay which isn’t exactly a “small” town, Canterlogic was a major manufacturing facility producing vehicle technology and whatnot.
We have only seen smaller parts of Maretime Bay - and almost nothing of the south-western part, which the writers had used as a “void” to expand the “world” first with swimming beaches, then rock caves, and then the amusement park. It’s a bit strange that the tram in Maretime Bay didn’t come to the beach in the south west, as it goes through the city and up to the northern suburbs.
