Add Yahoo as a preferred source to see more of our stories on Google. There are a handful of ultra-high-net-worth pursuits that sound tempting, but don’t really make sense. They’re typically wildly ...

In the small but exclusive world of personal submarines, there are two brands: U-Boat Worx and Triton. The two go mano a mano for the most part, offering a range of subs for different missions, ...