Semester at sea for high schooler

We have a 15 year old , Hugh Kane , who is one year ahead on school credits. Our family has been planning for a semester abroad for him before he attends university or tech school. We started planning and saving 8 years ago, and since he is a watersport champion the prevailing opinion is to be on a school linked traditional sailboat, exploring and learning.... for example, one school offers 4 high school credits per semester while stopping at many countries around the Mediterranean

Anyone have direct experience with such programs?  If so, could you help by details about the semester?  I have been reading reviews but having a Permies opinion could be grand

What a wonderful opportunity!

I don't have any experience though I would look to see if the school is accredited.

Or ask for reference for kids that have taken the course.

This must be really expensive.

Yes, we only are considering schools with 20+ years experience which have established accreditation.  With years of saving, and a 25% pledge from a kind relative who loves our teen, it is possible.  
As life teaches us, "it depends " on pricing a term abroad that will be a lifelong influence ( no phones except when on weekend port visits, etc!) on our man-child.

Hugh won a scholarship to sailing camp 3 years back and that opened his eyes.  He has read  Moby Dick
three times, loves Captain Bildad and his bluster.   He is a kayaker who has carved custom paddles ( one was chosen for an art exhibit  ) and swims 1 or 1.5 miles every morning when in training.  He won a gold at state swim championship this year.   Basically, half amphibian.  So, my wife and I want to encourage his passion for the ocean , nature.......... scuba, ...........new cultures.........and crucially the path to self discovery.  

Absolutely have read all reviews of these programs.  However I hope to find unsolicited opinions on these pages, thanks.  Oh I guess I am soliciting..?...

Hi Rico,

One of the many discoveries of my young adulthood was that sometimes a private school can be cheaper than a public one.  As you make your decisions be sure to weigh in all direct and indirect costs.

I was hoping someone with real experience would weigh in. My college had a semester at sea and everyone who did it seemed to really love it. But they were a bit older at that point, I'm not sure that makes a difference.
I'd also want to make sure kid is not missing anything during his senior year (although it sounds more like you're considering a gap year type thing). It's easy to be excited about going to do things but experiences like prom and graduation or whatever else that are part of your community are important memories to make.

Nowadays in internet times you can almost certainly find graduates of these schools if you search with the program name (this is an example, but for college age https://www.reddit.com/r/AMA/comments/1q7bs27/i_went_on_semester_at_sea_ama/?solution=8c802e19133da0038c802e19133da003&js_challenge=1&jsc_token=7afd7253fec22262ff1c52b1703fe9ecb4cfb27fd4fcebad7de0a6e4f14df6e0&jsc_orig_r= )

I was thinking back to a college student who did a year abroad.   This was back in the 80s.  She made speaking rounds of the various clubs and churches in the area and raised several thousand $$$.   Of course, when the year was over, she returned to those organizations with a follow up presentation.