Hi there are several ways to do this operation first what size sub do you have ,what means do have in mind to actuate mechanism,how many chanels to alocate,how much do you want to spend?

I like the hydraulic method as seen in my posts its easy to build and is not expensive smothe and very realistic operation.Then there is the mechanical way its more complex and less flexable in tight areas and can be much more expensive.

Engle makes a mechanism for there subs its a bit costly but works very well.

One could emulate that same system in Tecnkics Legos and if the space is adequate it would do the job very inexpensively as well.

Those are some thoughts that might help.Just remember that it must be robust ,waterproof,low or no maintenance,simple and not cost much,to me its a challenge to make all of those goals from things that are readily available and are not expensive so have fun and see what you might come up with.

Dave



http://www.youtube.com/watch?v=j0_hNDRKjMcthough not the same,the method is there,just a diferent mechanism.