I have a 1993 honda prelude si h23

on a hott day if i use my car all day smoke will come out the tailpipe. it looks like white steam. i think its the water. and yea the water in the radiator gets low.

but there is no water in the oil i check and this problem only happened 3 times in the last 2 months. There was a ton of smoke though. and every time it happened when i used reverse on my 5speed. when i shifted to first the smoke stoped

any ideas

is it the water pump or like the head gasket?