Sephiroth_C_Ryu posted... Both would use things they make themselves to fight. Nami has some magic sticks that can mess with air currents. Bulma makes/has access to space ships and time machines and submarines and all manner of such things.
Without prep time, it may be a stale mate unless Bulma is feeling cheaty and just uses the time machine to mess with history to prevent the fight from coming to pass, as Nami's abilities probably are not going to be very effective against most Capsule Corp equipment, and Capsule Corp stuff simply outclasses any of the Strawhat vehicles.
If no vehicles are allowed, but we say that the characters are in "to the death mode," Bulma just immediately pulls out a modern pistol and shoots Nami before she can reach her (which is pretty close to her initial reaction to meeting Goku the first time).
Most of the ways Nami wins is if Bulma just stays stationary without attacking because she doesn't realize its a fight yet (Nami's magic sticks don't really have a visible effect until one of those small cloud systems starts forming). And, in the event of vehicles, that we pretend Capsule Corp vehicles have none of the modern protection that vehicles have against lightning strikes.
Nami isn't some normal human while Bulma very much is outside of her intelligence. She's stronger and faster than Bulma. None of the Straw Hats are normal humans.