Can a sub be a wall?

[Pastel]

There's a port between two lands and opponents can't invade orange star's territory if they can't pass through the port.

Then is it a good idea to deploy a sub at the port?
I think the opponents can never attack the orange star's units if the sub sinks at the port though...
What do you think?

[Walker]

Yeah, the only way the opponent can get through your dived sub is if they get a cruiser or sub of their own that can go right next to it. Otherwise they won't be able to block it. Be warned though that 20k is a lot to spend to block an area, so I wouldn't advise it unless it's very strategically advantageous.

[Pastel]

As you say,it's too expensive as a wall...
Probably three artillery and some infantry are better than a sub.
Thank you for your advice.

[CO Raven]

There are some maps where it is really useful and effective. I recall one map where there was a central mountain area with ports that butted in as the only pure land routes in or out of the center area while held the 2 comm towers on the map. I sub locked both which bought me enough time in the center where my opponent couldn't stop me from taking both towers and the other properties after which the advantage became insurmountable. So there's a time and place for sub locking. Not to mention that it paid its worth many times over by forcing my opponent to build cruisers and subs to try to unblock the area. So don't do it just because you can. Do it because you have a goal.