rotting cucumber fruit

my cuces are growing fine, the plant is healthy, but the fruit itself starts of really nice and healthey ,then at about 2 inches dies at the end and starts rotting, any one know why
yet th plant itself is healthy

 

Blossom end rot, have a look Here

 

I asked my father in law to have a look as well, turned out i was over watering.

 

I agree with JWK, the plant is still small, needs to be a bit bigger before it produces good fruit.

Even then, if it has too many fruit developing, the same thing might start happening.

 

i have removed all the fruits now.