Is what it says on the side of the hotel closest to the port.
With a naval history back to the Middle Ages and before, it is not surprising that the town focuses on the maritime industry as well as its current status as the major French Naval Port (complete with submarine manufacturing and basing).
The only other comment I can make is that there is also a major fixation on the Titanic (since it made port here after leaving the UK and before meeting its doom). The local museum/aquarium complex not only features all sorts of wonderful submersibles but also more books on the Titanic than I know existed (much less in French).
I quietly slipped off the ship early and walked the town prior to anything opening. Or at least before opening hours as I know them. Then I realized that it was Monday. This is small town France -since stores were open on Saturday, they are not open on Monday.
As a result, I wandered the streets and back alleys looking at wonderful old stone construction, interesting trims, the Theater and scattered bits of architecture prior to stopping for Cafe au Lait and a croisssant prior to exploring the maritime museum’s outer lobby. I elected to skip spending several hours waiting plus the Euros needed to do the 45 minute walk through of a French submarine. Don’t think it would be that different from (pick one) DE/US/UK other than the language featured.
I made it back safely to the ship in plenty of time to relax and watch Cherbourg fade in the distance behind us with no intentions of being up at 0200 when we enter the English Channel portion of our 245 nautical miles to Harwich.