Summer Jobs/Activities For an Almost Sixteen Year Old?

Actually I think 15.5 is old enough to make your own decisions about how to spend your leisure time. If you don't want him to game, put the equipment for it away and tell him he can: a) do nothing productive b) volunteer somewhere to help his college transcript/pass the time/have fun--and let him figure out where (though you can help him research) c) do chores around the house to earn more time gaming (or money/whatever) d) do a project related to his chosen career field (build/write/create something) He is too old for camp, and too old to be scheduled by his parents. He needs to learn to make these decisions himself and you need to let him. And while I'm sure you didn't mean to, but your post reads like he's going to be in your way and be a nuisance, and not, you know, there to hang out with his family who loves him and wants to spend time with him.

What about learning to crew down at the yacht club/marina?

+1 for the junior counselor thing. Don't just call camps -try YMCA and the like, Boys and Girls clubs, local parks and rec centers, after-school care at places that are doing summer school like elementary schools, kids play spaces and game centers, etc.

I took summer classes at the local college that summer.

Does he like animals? The Humane Society or other local rescue groups may have volunteer opportunities for the summer.

On the further out-there side of things, he could build a tiny house. http://www.tumbleweedhouses.com/ That would be a lot of money for you to buy the parts, and one of the adults would probably need to help. But if he lives in it, that's probably cheaper than paying for a college dorm or paying his rent, and he'd have a house when he graduates high school! (More realistically, that would be multiple summer project, unless you are super dedicated.)

Try calling nonprofits and see if they need a volunteer to do data entry. A lot of nonprofits have a hard time taking on volunteers that young for liability reasons but usually anyone can do data entry. I volunteer at a local animal rescue occasionally and they can't have young kids volunteering without an adult but they have data entry they need people to do. They also run a small camp for little kids that they need help with. When I was a young teenager, there were several vacation Bible schools in our area. I don't know how you would feel about him helping out with one of those but that might be a possibility. We also had a few local clubs for young teenagers that would connect you with volunteer opportunities - is there something like that near you? Is he at all interested in politics? He could probably volunteer for the local party collecting petition signatures or something. The summer before my junior year, IIRC, was spent largely riding a bike around town with a friend, having sleepovers, occasionally doing something productive and flirting with boys. I wouldn't tie him up with too many things this summer. Try to identify one or two things that actually interest him and help him do those things.

I'm with Tomorrowful. I've been working since I was 14. It's the biggest regret of my life. Let him relax, maybe sign him up for one super-recreational outdoor thing to make sure he produces enough vitamin D, but I'd stay mostly hands off and let him rest up for life as a cog.

(Sorry, missed your point about classes feeling like summer school ... maybe something shorter and more focused on a fun activity would make it more appealing? http://www.digitalmediaacademy.org/locations/kids-teens-locations/university-of-california-san-diego/#teen has a slew of pretty cool-sounding one-week courses, for instance - they call it a "camp," but apparently it's not a sleepaway camp).