Saw this yesterday so thought I'd post it. I hadn't heard of it before, but ERT is a 2003 naval battle sim based around a fictional version of WW2. More info on it here:
[url=http://en.wikipedia.org/wiki/Enigma:_Rising_Tide]http://en.wikipedia.org/wiki/Enigma:_Rising_Tide[/url]
It's got good ratings on various sites (including 75% from PC Gamer) so worth a download. The original game also had Starforce protection but this release is DRM free. I burned the ISO to a DVD and installed it that way, but I think extracting it with WinRar or 7-zip and installing from the folder will be fine because it doesn't require a CD in drive.
Without further ado, link to download can be found here, provided by one of the game's developers:
http://www.subsim.com/radioroom/showthread.php?t=156626
Disclaimer: the developer has released it but I'm personally uncertain whether they are fully allowed to do so? Maybe they have full publishing rights or they've reverted back to them or something.
Edit: Oh I see, there were legal disputes between dev and publisher back in 03 which the dev won in 06.
Via:
http://www.rockpapershotgun.com/2009/10/04/enigma-rising-rip-tide/

There's a free games list here.

Holy shit, sim game!
Thanks for this.

Maybe gog should contact this guy and see if this can be put up on gog as another free game.
Thanks for the info and link.

I bought a boxed copy of this (the standard edition, published by GMX Media), too bad it seems the developers were scammed and didn't receive any of the money I paid for it.
The game itself is quite good, actually. It's been ages since I played it, so the details are a bit hazy, but I think people looking for something a little different (and deeper than the typical arcade game) will like it. Be warned, though, the waves will make you seasick. :-)