The experience was an adventure and a joy for Stan Winston and his monster-making team. Not only did they get to live in Rome for four months during filming, and even learn scuba diving, a recreational activity many of them continue to pursue to this day, but they also got to work with a director who was unusually generous with inviting their input. In addition to producing the creature effects, Cosmatos trusted Winston to direct the second unit action sequences. "George Cosmatos always let us take the lead in how to shoot the creature," noted Landon. "He was such a big-hearted person, he would throw up his hands, and say 'I don't know what I'm doing.' He'd just admit it and let us do what we knew how to do. We know what our characters can do and we know the best way to use them. We're thinking about what our characters are going to have to do on the set the entire time we're building them. So we are goldmines of information and knowledge. Some directors recognize that, and really rely on us."
The movie is set in the year 2027
Deep Star Six (1989) was the first release of several underwater-monster-themed feature films released during 1989-90, including The Abyss (1989), Leviathan (1989), The Evil Below (1989), and Lords of the Deep (1989), and 'The Rift' (aka 'Endless Descent', 1990). With the exception of 'The Abyss', none of these films were box office hits.
The creature effects team encountered some language differences during the making of Aliens (1986) in England, but the challenges were much bigger in Italy. "I always keep a log of everything we order on shows, just in case accounting comes back later and asks about it," noted lead creature effects mechanic and on-set technician Richard Landon. "In my log from that show, you can tell that there were some real language issues, because a lot of times, instead of words, I drew pictures of nuts or bolts or that kind of thing. I would quite often have to draw a picture just to make it clear what I was talking about." There were cultural differences too, such as the Italian's crew tendency to drink large amounts of red wine at lunch. "They'd say, 'Here, have some wine!' remembered Mahan, "and we'd say, 'Uh, thanks, but we're not allowed to drink while we're working.' Of course, every once in a while, we'd sneak a little, but nothing like the way those guys were drinking it down."
When Doc is analyzing Sixpack's skin sample, the computer reports back the phrase "of unknown origin". This is a winking nod to director George P. Cosmatos and star Peter Weller having previously collaborated on the movie Of Unknown Origin (1983).