Sounds like you're talking Spider Rigging or Pushing. Kinda sounds like your anchoring process is spooking the school away from their spot. If you're not rigged up with long rods & rod holders, then Long Line Trolling sounds like your best option. You "could" use one rod in each hand and troll, but getting and keeping a jig or jig/minnow down close to 15ft deep will likely require some added weight.
I used to Push jigs in my pre-Livescope days ... and I'd use 1oz weights @ ~1mph. In order to keep those jigs at or just above 15ft deep, I'd have close to 25ft of line out and try and keep my lines close to a 45deg angle. Otherwise, once I found a school, I'd just back off of them and cast (either with the countdown method or cast well past them and slow roll the jig).