Well, the thing is... this ship is quite small. As such, I would envision a "lounge" on such a ship being no larger than either something like on a 747, or maybe a small breakroom, at a work location... just enough for a few people to unwind for a few minutes... a table and a few seats, a replicator, and maybe a viewscreen or table game. Again, just my take.
I dug up some URLs for assorted research ships for sale, to help provide some real examples of space usage and fittings on such ships. Not an exact match for the Needle since at least some of the time these ships have open deck space available, but something to get ideas from. (most of these have another page with additional photos. See the "click here for more photo" link just above the photos on the given page. I tried to just pick ones that showed common areas.)
a bit on the richer end:
<= a "Whiskey" class sub. The staff room photo may be of interest (though very grainy and the angle doesn't show all that much.)
(scroll down and click for interior photos)
More examples can be gotten by Google-image-ing for "boat interiors" as I suggested above, and especially for "sailboat interiors". Sailboats usually have to be even more mindful of space than powerboats, so they sometimes provide better examples of getting maximum usage out of given spaces. Naturally, a lot of what you'll turn up on the web are luxury designs, but if the space usage works just rework it with less fancy materials (i.e., generic ship paneling instead of expensive woodwork.