Splash down

[KArllllllll]

i got the mission where i need to test a engine in the water, but when i land in the water the engine just gone, its like when i hit the water all my engines and fuel tanks just Disappeares

[peteletroll]

Probably you're hitting water too fast, and your engine breaks. Add parachutes.

[bewing]

Each part has a maximum speed for surviving when hitting the ground or the water. As said above, you are just hitting the water too fast for the engine to survive.

Personally, I think that it's easiest to make a rover and put the engine on the rover. Then drive the rover down to the shore and into the water. Then test it, and drive back to the runway to recover 100% of your funds.

 

[Spricigo]

1 hour ago, bewing said:

Personally, I think that it's easiest to make a rover and put the engine on the rover. Then drive the rover down to the shore and into the water. Then test it, and drive back to the runway to recover 100% of your funds.

Nahh, SRB+decoupler+lots of parachutes is by far the easiest (and least glamorous) way

[KArllllllll]

Thanks for all the answers, im hitting the water with a speed of ca 6-7 m/s

[Laie]

8 hours ago, KArllllllll said:

like when i hit the water all my engines and fuel tanks just Disappeares

Everybody knows that splashing into water is a gentler landing than impacting on solid ground, but unfortunately, in KSP it isn't.

All parts have an "impact tolerance" listed in their stats. Hit the ground (or the water) faster than that, and they will be destroyed. However: if you hit the ground, the part takes some of the shock of the impact before it explodes, and the explosion, too, is likely to slow the fall of anything on top of it, which will hit the ground a moment later and a little gentler. This can work like a crumple zone, really.

While if parts enter the water, they just disappear. That way, whole stacks can vanish in an instant.

But the TL;DR of it all is: you're coming down too fast. Bring more parachutes. Or have a little fuel and run the engine in the last moments before impact. Or follow @bewing's advice and build a rover.