How do people do stock boats around here?

[Guest]

I figured I'd give it a try. Two empty orange tanks with some outriggers and basic jet engines seemed to do pretty well for a first test (tweakables are awesome) but before I start building something more complex I had a few questions.

Can the engines go underwater? Is there a better method of locomotion than basic jets? How full can tanks be before they lose their bouyancy or does it matter at all?

Edited January 6, 2014 by regex

[DeMatt]

I haven't tried building boats at all, but I'm pretty sure every stock part floats, period. The game's about building rockets after all.

The problem is that running into the water is only mildly more yielding than running into the ground. So any boat that would actually develop any significant speed would splatter when it tried.

[Guest]

I have answered my own questions through experimentation.

[ThatKerbal]

that'd be cool, a launch on a boat!

[irongut]

I haven't tried building boats at all, but I'm pretty sure every stock part floats, period. The game's about building rockets after all.

The problem is that running into the water is only mildly more yielding than running into the ground. So any boat that would actually develop any significant speed would splatter when it tried.

Search for the water speed record challenge thread. You would be surprised at how fast it is possible to go in Kerbin's oceans with a rocket powered boat. (well over Mach 1)

IIRC the people in the challenge thread put air intakes under the waterline to make their boats work better. They have negative drag or something.

[Guest]

I was surprised at how fast I could get the boat above to go with a few adjustments. At first it would break apart if it went above 5m/s, so I tried moving the engines completely underwater and forward of the COM. This raised the nose when underway which allowed slightly faster speeds so I suspect that, initially, it was a problem of too much drag or pressure with the nose driving under the water at speed. Following this logic, I removed the side tanks (also because you can't actually dock the little jet hopper craft using KAS because the legs just clip into the platform, so I didn't need that fuel) and moved the engines so that the center of thrust was only slightly ahead of the COM. Since the ship was already a bit rear-heavy at that point it floated with the nose tilted up. This actually works out better with a payload anyway. I took it up around 10m/s and suspect it could reach 15m/s at full throttle.

Edited January 6, 2014 by regex