Fogging fix

Fogging can be a real problem because it interferes with visibility. Humidity and condensation will always be an issue because of air to water temperature differentials, so minimising moisture in the housings is essential. the problem can be minimised with a little effort, especially since we can easily access the BlueROV2 internals. Using one or both of the methods listed below has the optimum outcome for the greatest variety of environmental conditions.

1 – equalise the ROV in dehumidified room: in a small room with a dehumidifier, remove the electronics enclosure vent plug and leave the ROV to equalise for several hours. You may find similar results in a well air conditioned room overnight, depending on relative humidity.

2 – desiccant: use desiccant to remove humidity from the electronics enclosure. We suggest rechargeable, moisture indicating, silica gel, which you can purchase through us or other suppliers.

Enjoy!

ROV-mounted sediment corer

[cs_content][cs_section parallax=”false” style=”margin: 0px;padding: 45px 0px;”][cs_row inner_container=”true” marginless_columns=”false” style=”margin: 0px auto;padding: 0px;”][cs_column fade=”false” fade_animation=”in” fade_animation_offset=”45px” fade_duration=”750″ type=”1/1″ style=”padding: 0px;”][cs_text]A new ROV- or AUV-mounted product was announced last month by Ocean Scientific International in the UK, which will recover a 400mm sample (300mm sediment and 100mm supernatant water) from depths of up to 1200m: Subsea World News 22jan18[/cs_text][/cs_column][/cs_row][cs_row inner_container=”true” marginless_columns=”false” style=”margin: 0px auto;padding: 0px;”][cs_column fade=”false” fade_animation=”in” fade_animation_offset=”45px” fade_duration=”750″ type=”1/1″ style=”padding: 0px;”][x_image type=”none” src=”http://www.undersearov.com/wp-content/uploads/2018/02/osil-sediment-corer-320×427.jpg” alt=”” link=”false” href=”#” title=”” target=”” info=”none” info_place=”top” info_trigger=”hover” info_content=””][/cs_column][/cs_row][/cs_section][/cs_content]

What is an ROV?

A remotely operated underwater vehicle (ROV) is essentially a tethered underwater robot or drone. They do not carry passengers, are operated by a pilot aboard a vessel, and feed live video (and other data) back to the surface via the neutrally-buoyant tether. These vehicles are typically used instead of divers when conditions are too dangerous or too deep to dive in.

Bigger, more expensive and sophisticated ROVs are common in deep water industries like offshore oil drilling, where they often work in rough conditions, at depths >500m, and carry power equipment like torque tools and manipulator arms for underwater tasks like welding or construction. More about these work horses can be found at: RigZone – How Do ROVs Work?

ROVs are also invaluable tools for scientific oceanic exploration, used regularly by organisations like NOAA and AIMS. They can provide 24 hr observations with video and other scientific measurements relayed immediately to scientists at the surface: NOAA Ocean Explorer – What is an ROV? or watch a short video: ROV Exploration.

More recently, smaller, highly manoeuvrable, inspection-class ROVs have come onto the market to observe subjects at depths <100m (like the BlueROV2). These vehicles are more like underwater drones: lighter, less expensive, easier to use, and powered from on-board batteries. A detailed review of inspection-class ROVS can be found at Journal of Marine Science and Engineering 16mar2017

No matter what type is used, ROVs make exploring underwater faster, safer, and easier than diving, especially in crocodile infested waters!

Enclosure leak spotting

There is nothing more frustrating than failing a pre-flight vacuum test the day before an important dive.  We suggest the following steps to help find that persistent leak:

  • Mix a liquid soap solution in water (more soap than water) and fill into a small spray bottle (at least 1/3 full).  Dishwashing liquid will do but avoid anti-bacterials
  • Place a towel under the ROV and close all enclosure vents except the leaking enclosure.  Make sure to protect the topside FathomX card from spray
  • Using the brass fitting and tubing from the vacuum tester, connect the leaking enclosure’s vent to a bicycle hand pump (NOT electric)
  • Carefully spray the leaking enclosure with the soap solution.  We suggest starting with the rear end-cap and penetrators.  If you aren’t able to find the leak there, repeat with the front end cap and flange edges.
  • Gently pump air into the enclosure and look for bubbles.  One or two pumps should be sufficient – too much pressure will cause the end caps to pop off.  The bubbles will narrow down the location of the enclosure leak(s).

Possible causes could be a loose penetrator, a cut or broken o-ring, dirt or hair on the o-ring, not enough silicone, etc.

Happy hunting!