No I don't. But basically what I went off on was this:

Of Skyrim, only Solitude, Windhelm and Dawnstar have the capability of handing shipments via docks. Dawnstar is too small to handle anything much larger than a small ship but is the only one with a fully functionable dock. Windhelm's dock isn't capable of accessing the open sea as the mouth of the river near Yngol Barrow is shallow enough to cross without swimming. Meaning any ship coming in or out has to be empty to have a shallow enough draft to make it past this area. Also compounding Windhelm's problems is that the North Wind is almost stretched out across the river. Leaving little to no room for any other ship to pass it.

Solitude has a semi-capable dock system as the river is deep enough to support larger ships and those ships can both arrive and depart parts of the dock from the river. However, the Red Wave which is constantly docked there, cannot leave the docks. Due to the orientation of the dock, it would have to sail upriver first, then navigate around the docks. Add in the highly potential damage from the outcropping of rocks just southwest of the ship and that ship will never be able to get out of the dock without damage.

A general problem for all three cities is the icebergs. Bethesda may have gone overboard trying to get us to believe in the arctic conditions and put more icebergs than necessary, but the number of wrecks and permafrost in the area suggest that the area typically does have significant ice flows. Looking at the map of Skyrim, the river that flows by Windhelm is nearly completely blocked by ice and/or icebergs. The area up near Solitude also has significant build up of icebergs of large sizes. Dawnstar also has iceberg problems, but they are further out. Basically, any ship heading in to or out of any of the seaports will take damage and/or be sunk at some point. I understand that boats can be built that can take damage from icebergs and keep floating, but the ones we see in game are all wooden and probably wouldn't last as long.

Moving slighty south, Morthal has several boats docked but has no real space for them to be used. There is a bit of a lake to the east, but the water is waist deep at most. There's also a bit to the west, but due to the waterfalls above, the current would be strong against the boats. Further out is swamp land that again is mostly knee deep and too shallow for the boats to reach the river or open sea.

Further to the south and east is the Rift. You have Lake Honrich near Riften and Lake Geir near Ivarstead. Lake Geir empties into two large waterfall systems meaning the only traffic in the lakes and joining river is from Ivarstead to Riften and back. If so, there should be a dock at Ivarstead which there isn't. So the two large boats docked near Riften can only go between docks located about 100 feet from each other. (Horrible estimate) Plus the water west of Goldenglow Estate suffers from the same issue as near Yngol Barrow and is too shallow for heavy boats to use. A bit further up the river around Sarethi Farm, the river is thin enough to jump across. So the large dock system at Riften is basically useless as the boats are only useable in Lake Honrich.

Lake Ilinalta down near Falkreath presents a really odd issue. Shipwrecked mostly beneath the water is an extremely large ship. At the lake has no ship building facilities and really only a small dock a bit east of Ilinalta's Deep, how did the ship get on the lake and what was it's purpose? A lake that small has no use for a large ship and what would a large ship be used for without docks? The river leading from the lake has several small and several large waterfalls so any of those ships wouldn't have been able to sail up the river. Also, the fact that Ilinalta's Deep has been claimed buy the lake and that there is a nordic barrow (?) underwater, it'd be reasonable to think the lake hasn't been there for long. Which would mean the large ship is a recent addition added to the lake.

Finally, one that jumped out at me within the last couple of weeks is the sawmill at Falkreath. There's no way that the small pond of water is either enough or contains a swift enough current to turn that water wheel.

The water system in Oblivion is even worse. The Imperial City is shown to have two massive ships docked and one quest even has you out at sea sailing on one of them. But there's no way either could get past Fatback Cave due to the shallowness of the water and the amount of rocks at the bottom. Even if one could get a ship past it and into the lake at Bravil, the river physically stops at Leyawiin. There is no way for a ship to get to or from the open sea from the Imperial City.

That's basically what I wrote before, I can understand that Skyrim (and Oblivion) was scaled down in size and thus some of the waterways aren't represented as they would if the land was the actual size.

PS - Bonus question: Where does the water around Dragonsreach come from? It sits on a hill and the water is constantly draining away but the water level never goes down.