Preventing an injury is easier than fixing an injury, and thus I'm logging my first instance of mild pain in my knee joint.1 I felt the pain after 3 hours of surfing Playa Negra and then spending another hour on a carver.2 I am fairly certain that the pain is coming from having poor technique while I was practicing new moves on the surf skate. I was compressing and torquing to get sharp bottom turns.
I found a random video on youtube of one guy who evidently went through the trouble of constructing a model of the knee so as to better understand how to fix the same problem as I am having now. So I'll leave it here for my future reference.
One piece of advice that I've now received from two athletes regarding injuries in small joints/tendons is to focus on making those smaller muscles very strong. So next on the to-do list is to figure out a series of workouts I can do to improve my knee joint strength as well as my wrist strength.
Knee pain went away after about 2 hours, and I had no knee trouble while surfing today.