As cheesie as it may seem, compared to dedicated flight sim programs, this was actually my introduction to the flight sim world on or around 2008, early 2009. Then came X-plane 7 for me in June 2009, followed by FS9 in June 2010. Okay... a late comer of sorts, but better late than never.
I always lamented the fact that Google Earth has never found a way to incorporate "spot views" of the aircraft into their "sim", nor a greater selection of aircraft... but for what it is (HUD cockpit views and all), not bad.
Haven't used it in a good long time, but I believe you can now take your plane, dive into the ocean at 800+ mph and go down into the murky depths below. And I don't even think it slows you down but 10 mph... the transition from air to water! LOL
MSFS 2004 v9.1 & FSX Deluxe Edition w/ Acceleration Pack; Windows 7 Ultimate 64-bit; AMD FX 8120 8-core processor 3.1Ghz; XFX R7870 2GB GDDR5; Corsair Vengeance 8GB 1600; Corsair 600CX PSU (600 Watt); Western Digital 500GB HDD; Biostar A880GZ AM3+, 125 Watt Max TDP MOBO; Antec Kuhler 620 water cooling