navigation transit markers造句

There are navigation transit markers alongside the cut to enable powered boats to check their speed.
There are navigation transit markers just downstream of Bourne End Railway Bridge, to allow river users to check their speed.
There are navigation transit markers alongside Port Meadow upstream of Medley Boat station, to allow river users to check their speed.
It's difficult to find navigation transit markers in a sentence. 用navigation transit markers造句挺难的