The almost-identical Vane tugs come in two sizes . . . externally  distinguishable by the height of the  upper wheelhouse.

Contrast the tower of  Bohemia above with that of Sassafras below.  Some I hear call the Bohemia etc. as the 4200 series and Sassafras the 3000 . .. as in horsepower.

Elk River and Oyster Creek . . .  size?

Bohemia and Sassafras (?) again.

Anacostia . . .   size?

Patapsco . . . size?

You were right if you grouped Patapsco and Anacostia with the 4200s, and the other two with the 3000 series.

I wonder about the communication going on here . .  a line of kayaks heading up the river as Elk River is attempting to turn to port aka “to the left”.

All fotos by Will Van Dorp.

Click here for more info on the Vane tugs.