This little submarine named Trieste was actually used by Jacques the Lego diver in his deep water experiment on lake Iseo in Italy in 2015. Check the story out at http://www.deep-z.com
Discover the video of the project here: https://youtu.be/Ym3eYgsCfV0
This part is designed for Laser Sintering. Good material properties and lots of geometric freedom. It's a very nice toy for kids as well! Note that for this model, the mounting feature (shown on some photos under the sub) has been removed. Looks better at home this way!