I’ve done 2 tandem jumps. It was awesome. I looked into doing the school to jump solo, but the time and money to get into skydiving is more than I want to invest right now. I’m more sure what option you’re talking about to do 25 tandems to jump solo. Doing the USPA course you start with ground school. Then your first jump, you jump solo with 3-4 instructors surrounding you. Then as you progress through the training you jump with fewer instructors and proceed through more advanced maneuvering etc. That’s the gist of it at least.