[zx10guy]

Ran across some Youtube videos of some RC jet planes. Simply amazing.

This one is a giant replica of an F-14:

This one is simply just nuts. A fully functional STOVL F-35:

And Tyler Perry's giant RC C-17 with a 21' wing span. The video also shows other RC planes in his collection:

ETA: Forgot to mention the skills of that professional RC pilot. Never thought RCs could be ever flown that way.

[2000cs]

Some amazing sail boats, too. Foils, for example. There have always been a lot of really good model builders, now there is a lot more cool technology for R/C stuff.

[DrVenture]

This is really cool due to the slow flight that makes it look to scale.

[3.0L]

I’ve been into RC since early 1970, right after I separated from the Army.
My first radio system was a 5-channel Heathkit. Taught myself how to fly.

Since retiring, my RC fleet has grown to about 30 aircraft including jets,
gliders, aerobatic airplanes and scale airplanes. Today’s radio systems are
incredibly sophisticated including telemetry, forward programming, thrust
reversing and on and on.

[2000cs]

Here is an example of a trimaran with foils. Based on the very popular class DF95 monohull with tris added. 3D printing has a lot of hobbyists creating amazing new boats.

A topic I’ve toyed with but never done anything about is weight shifting. Any sailor knows you want to shift weight to the windward side every time you tack. Quickly. A swing arm would work, but create too much torque (kind of like torque steer on a fwd car). Water could be pumped from one side to the other in center chambers of the tri hulls. A screw mechanism could move weight (but fast enough?). Etc.

[Alfisti]

You are excited to have a baby, you find out it is a boy, whole life ahead of him and you name him Tyler.