Nice, a balance for a change. Both camps have truths to be gleaned but if you've only done fair weather chartering, I'd suggest the following:
1. Determine the boat to go to sea in (much to consider here) and buy it.
2. Outfit that boat and get it out in marginal weather to sharpen your skills.
3. Once you're comfortable with that level, take it out in worse conditions and practice some more.
4. Use the resources available to avoid nasty weather when ya do finally go.
5. When ya get caught in the crap (this will happen) fall back on what ya learned in steps 3 & 4.
This is a very abreviated list and I'm certain many of the more knowledgeable residents will chime in with additional info. Good luck with your endeavor.