Ballast system suggestions

[Scrappy]

Looking for the best option for controlling buoyancy on my 1/6 scale submersible. I have been researching many different systems, was looking for the most common, most usable (plan to use sub a lot) system. Any advice will be greatly appreciated. Thanks,

Scrappy

[He Who Shall Not Be Named]

Gas type. Simple. Common. Usable.

[Scrappy]

How many “blows” do you get from a tank?

[redboat219]

For your Alvin a water pump.

[He Who Shall Not Be Named]

How many “blows” do you get from a tank?

Ten to Fifteen with the gas-saver device.