I don't think that last part I posted was a help, so I'll add this thought. I don't remember if the periscope showed up in my workshop after completing the mission or not, but I'm missing out on something very basic somewhere and am always searching around. I know when I got my first medal that I had to activate, I couldn't figure out where to find the medals to activate them, and the periscope may have been something similar to that. I keep clicking on the words that are underlined that then take me to screens that I don't know how to get to otherwise. I bring up the medal one as that's one I've had to check a few times already after buying crystals and I fuddle around trying to remember how I got there the first time.

I certainly don't have answers as I've only been playing a couple of weeks myself, but I'll help with my little thoughts as I can for the struggles I've undergone already. I have tons of questions myself but figure that the missions will eventually put me in the right direction for things.......lol.

When I got mine, I equipped it in the workshop on my shipyard. But it actually broke a few days ago and now I don't have one anymore, but I'm still seeing the extra regions that I did when I equipped it to begin with.