What was the problem? You didn’t pull enough downhaul? Btw to do this easier, more precisely and to extend the life of the line I’m using a rig winch:
www.the-house.com/ch200zz-chinook-windsu...AM42-7hoCwPwQAvD_BwE
I also keep a small rigging cleat in the pocket of my shorts for in the water tuning.
Also, why are you using a seat harness? It’s more difficult to hook/ unhook and seems like you are starting to develop bad habits early on. Things like “goofy foot” and low boom, short harness lines etc. are wrong and you should avoid getting used to.