This is my first float plane, after getting into and flying RC for three years. It's a Hobbico Superstar ARF 40 with Great Planes J3 Cub ARF floats, powered by a Tower 46. I found lots of useful suggestions in this forum, and after about a dozen flights on this bird here are some conclusions:

1. Waterproof servos are not. Tracking down and blocking every source of water entry is a MUST. Most of the "debugging" I've had to do involved servos that died due to water penetration. The most common failure mode was "trim drift", followed by either full travel in one direction or complete unresponsiveness. I tried the HiTec HS-5645MG servos, which are advertised as waterproof, and they are NOT. To prevent water entry, I pack the end of each pushrod tube with Vaseline before flight. I've used RTV in the wing saddle, but it's not enough by itself. I put a layer of Vaseline on the RTV, put the wing rubberbands on, then use colored packing tape as a further barrier under the wing on the saddle joint. This works 100%.

2. I set the wing - float incidence at about 1 degree positive for the wing. This seems to work well as long as the CG is about 1/4-1/2" aft of the steps on the floats. If the CG gets too far forward, the plane tends to bounce a lot on takeoff. I ended up with the CG about 1/8 of inch forward of the forward most point recommended by Hobbico.

3. I used two servos for rudder- one water, one air. They are both in the fuse, and the water rudder flexible pushrod assembly runs from the right side of the fuse to the float, where it is held in place with epoxy.

4. Lots of power is a must. The Tower is a strong 46, but I wouldn't want anything less. The high lift wing of the SuperStar helps a lot. The airplane handles well and is fairly responsive even with all the extra weight. (The floats weigh almost as much as the airplane.) Always, always, warm the engine up completely, shut it down and refuel before attempting a flight. This minimizes flameouts.

5. The water handling with this combination is SUPERB. (The GP floats have a huge water rudder.) I tried a Lanier SeaBird last year, and never flew it because it STUNK on the water. This one goes where I point it and has no tendency to nose over or flip over in a crosswind.

6. Takeoffs are straighforward as long as you always go into the wind. Don't even consider taking off in any other direction. Full throttle, full up elevator until she gets some speed, then relax and steer. When she's hauling, start applying backpressure until lift off.

7. Landings: Start downwind at about 100 feet or so altitude, throttle back to idle and set up a slightly nose down glide. Maintain this all the way through base onto final. The turn on to final will be at about 50 feet altitude. Throttle up to just over idle and establish a level attitude. The bird will sink. When within 10-15 of the water, throttle back to slow idle and flare, flare, flare. A nice slow touchdown with the nose high gives a sweet landing every time, and crosswinds are not a problem as long as you keep the wings level. Any faster, and it skips like a flat rock. In order to get nice landings, I find that I must have the bird crossing in front of me, L-R or R-L, and try to set up the touchdown point directly in front of me so I can see it well. Any other way doesn't work well because it is very difficult to judge the airplane's attitude as well as it's height above the water.