Rank amateur...
Good grief, if your master escape plan involves an underwater getaway (in winter!) then you'd better spend some of your ill-gotten gains on:
1) A rebreather tank so you don't leave a trail of bubbles (and maybe a faster model submersible?)
2) A decoy air tank to fake your own drowning
3) A decoy body (optional) - depends on access to a morgue/corrupt undertaker
4) A covered location to surface in & second getaway vehicle (the most common one on local roads c.f. Drive, The Sentinel, etc.)
5) Route to your non-extradition country of choice with home already set up (Heat, etc.)
Various other steps too, but jeez, if you're going to go to the effort of maintaining a Ponzi scheme, plan the out!
He'll have plenty of time to do 20/20 hindsight planning in the pokey, I'm sure...