1. Making Your ROV Buoyant

2. Buoyancy vs. Ballast Buoyancy Ballast The ability to float in water.
Weight added to reduce buoyancy

3. How buoyant?
Positive Buoyancy – Enough buoyancy to make something float on water surface
Negative Buoyancy – Lack of buoyancy causing an object to sink
Neutral Buoyancy – Enough buoyancy to make an object float in the middle of the water column

4. Should your rov be buoyant?
You want your ROV to be close to neutrally buoyant
But it should be just slightly positively buoyant
Why? In case your tether breaks, your ROV will eventually come to the surface

5. Where to position buoyancy and ballast
Buoyancy on top
Ballast on bottom
You want a large distance between your center of gravity (CB) and your center of buoyancy (CB)