ballast tank equipped 1.25" SubDriver now in production

[small sub guy]

Can you tell me on (image 4) what is the purpose tube blue in color coming out of the end cap and where does it connect?

[He Who Shall Not Be Named]

A very small diameter system used to control, manage ballast water, and propel small scale r/c model submarines. Developed to animate 1/144, 1/350, and like sized scale plastic submarine models currently available on the market. We call it a 'SubDriver, or SD for short.

The availability of very small servos and other r/c devices has made the very compact 1.25" diameter SD possible. The SD can be arranged as either a static or dynamic diving type system, i.e. with or without the water ballast sub-system: For the exceptionally small model submarines, demanding a shorter SD, a dynamic type is used; larger models equipped with the static diving type SubDriver.

These and other r/c submarine products are available from http://www.sub-driver.com/

http://youtu.be/Lu6x3vI2Yek