[ngc6656]

To have been awash with water, Mars had to have two things, the needed temperature range and sufficient atmosphere.

It is hard to imagine Mars had bodies of water approaching the size of Earth's oceans. Thinking regionally, one can imagine the formation of temporary streams, ponds, lakes, perhaps even small seas as comets of various sizes collided with Mars.

[LibWhacker]

Yep, I don't think there is much doubt that Mars was much a warmer place in the early Solar System, and probably had a much more substantial atmosphere as well.