weird bug with trireme class

[Wahazar]

I have two units, both belong to the Trireme class - can't go onto Deep Ocean tiles :

One unit (canoe) can't go to tile 36,5 (native coordinates, shallow Ocean), while another one (galley) go here without problems.
No idea, why such different behavior?
Save game attached (augmented2 modpack)

[Alien Valkyrie]

EDIT: Misunderstood the question; see Ignatus' answer below.

[Ignatus]

Canoes have not only "Trireme" class that restricts units to shallow ocean, but also "Trireme" flag that restricts them to safe coastline. Galley has only the class.

[Wahazar]

Thanks for clarifications. So it is not a bug, just a feature. Interesting, so it is possible to make for example hovercraft capable to drive on land and along coast but not capable to go far from coast.