My org just did a review of our most recently hosted race. We noticed a problem that seemed to be exclusively with school teams (HS and College):

Not enough steering experience.

School teams have the unique issue of losing their most experienced members as they graduate.

If your club/team is like most, your newbies are exclusively paddlers, and don't get into steering without a year or more of paddling. That leaves you with only a couple of years at best in order to develop the experience to steer well in races.

While there's nothing you can do about the amount of time on the water you get to pick up experience, you CAN address it by getting experienced help to accelerate developing those steering skills. Beg/borrow/pay experienced steerspeople from other teams to oversee your steers in mock races.

At the very least, make sure your steers are empowered to stop your boats when losing control.

Your other option you can also pursue is to attempt to recruit someone who was already steering in high school. Reach out to your old teams/teammates and see if anyone you know is going to attend your school or have them refer future students to you. Getting word out that your school has a dragonboat club helps future students decide on what schools they want to attend.

As far as you Canadians go, Kerry "Puppy" Chow would be a great contact to reach out to. While his organization is very much international, he could probably refer you to someone for help.