Inland passage (6)
I believe the answer is:
seaway
(Other definitions for seaway that I've seen before include "Ship route" , "Route for a vessel" , "Channel for shipping" , "Inland route for use by seagoing ships" , "Channel open to ships" .)
I believe the answer is:
seaway
(Other definitions for seaway that I've seen before include "Ship route" , "Route for a vessel" , "Channel for shipping" , "Inland route for use by seagoing ships" , "Channel open to ships" .)