Both you and your wife and hugley3 have specific knowledge that could be leveraged prior to heading out. You could put together an information product or training that generates dollars via limited marketing. You could have a product that helps consumers make better insurance choices or a training that helps agents generate or close more leads.
The boomers are aging fast (aren't we?) and the market for health info is bigger than Buster Brown's market in the 60's. Do you think that a nurse with 25+ years experience has credibility? Most people trust nurses more than doctors. I'd buy her ebook on the right topic.
You could also divert your 401 contributions into investments for a few years that generate dollars NOW. You don't need to make a million from any of these. 2-3k per month and you should be able to extend your cruise as long as you want to.
Hope this helps and good luck with your goals. Having the goal puts you way ahead of the pack.
Oh and Huguley what about a piece on the 10 biggest pitfalls for network managers or the 5 biggest mistakes made with networks or something? You are probably geeky (compliment) enough to do a web based training thing. Don't work while you are out there, work now and let it work for you while you are gone. Compared to sailing, work sucks.