Yes! I had trouble deciding whether I should consider cities like London, Hamburg etc. coastal for a quiz about the largest coastal cities in Europe. I decided to include them there, especially since they have some of the largest ports in Europe, meaning that they are closely connected with the sea, so for the sake of consistency I excluded London here with a caveat about cities on river estuaries and cities whose urban area reaches the coast.
The reason I chose to include Glasgow is that the urban area seemingly ends right before the Clyde empties into the sea, at least from what one can tell by looking at the width of the river and Google Earth's delineation of the coastline. This isn't quite the case with London, where Gravesend, for example, can well be considered 'coastal'. Of course, the limits of the estuaries of rivers like the Clyde or the Thames are somewhat vague, so I'd be happy to hear more opinions on this.