The first one I caught was the Red Scorpionfish on the Boat on sea tournament. I was using Luck Potion 2, so that helped.
The second one was the Kaluga Sturgeon and this time I was not using any potion. To my lucky surprise this fish was also a new wr. The old wr was 109 cm and the new is 151 cm.
The third 5-star was yet another Red Scorpionfish!
Lucky Potion is best used where you need experience points (Boat on sea) and also in the Lake run tournament where the longest total length of fish wins, since some of the rare fish are huge (Mekong Giant Catfish).
Magic Watch is best used in the Magic 15 tournament where you need to catch 15 fish as fast as possible.
Radar is good for all tournaments.