From: "patrick mitchel"

Okay, they're slow and yeah, they oughta see eachother, that doesn't stop
ship from hitting each other and some of them are only doing 15 kts or so.
As an aside, I witnessed a slow race where the goodyear blimp and I think it
was the fuji blimp (one of with the vectoring thrusts engines) were out over
the water just off Long Beach, Cal. where they were trying to maintain their
position. The goodyear blimp must have dumped some ballast in the process as
it was pointing severly nose down while the other blimp with the vectorable
thrust was sitting there level. Pat

Goodyear's blimp didn't dump ballast. I don't think their blimps even have
ballast. Their blimps are close to neutral buoyancy and they use the engine
power to gain or lose altitude using the elevators.

Other people's blimps tend to use thrust vectoring by rotating the engines.

Dan, U.S. Air Force, retired