Bridge Command is an open source (GPLv2) ship simulator, developed for training purposes. I've developed it for many years with Blitz3D, but have now re-written it with Irrlicht, and it's now available as a beta to test for Windows, OSX and Linux.
It can be used as a standalone program, or networked (Enet library) with an instructor controlling what goes on in the scenario. With this networking, it's also possible to set up a panoramic view, with a computer running each view, all duplicating from the 'master'.
It's available at https://www.bridgecommand.co.uk
, from the downloads page. As it's still in beta, most of the website is about the Blitz3d version. Version 5.0 is the new release using Irrlicht. Please post here or use the feedback form on the downloads page to let me know if it's running for you, as well as and any problems or suggestions.
The source is at https://github.com/bridgecommand/bc