Another lockdown… another commute

[Shy Guava]

It has been determined it was an uncharted geological obstruction.

So it's turned out to be Mendip's fault then? What use is all this high priced technology and personnel when they can't even see mountains in the South China Sea from the Blaxk Sea? Cunning Chinese have probably sprinkled these things all over the place. Mendip will have to crank his forward facing camera up a few notches to be safe as the Russkies might also have the technology.

[Mendip]

^ I don't think it's really fair to pin this on me.

Wouldn't sonar have seen that?

Subs almost never use active sonar, anyone listening will know where they're at.

I haven't followed this story but I do know that any sonar (even if it's turned on) is only as good as the operator. Our ROVs have forward facing 'Obstacle Avoidance Sonar' (OAS) but several times I've known an ROV pilot to nod off on the job and fly the ROV into an under water obstruction. It would seem strange for a submarine skipper to do this with his submarine but you have to remember that working at sea is probably 90% monotony and routine and it's easy to lose concentration. You'd like to think a submarine would have some alarms going off before a collision though.

Strangely enough, we've been having a problem flying into tree trunks. There seems to be loads of big tree trunks sticking vertically out of the seabed in the Black Sea and it seems that the logs must drift about until they become waterlogged and then sink vertically down like spears and embed themselves into the soft seabed. I have no idea why there are more in the Black Sea than anywhere else I've worked... maybe because due to the anoxic conditions and absence of bottom current these tree trunks just remain on the seabed forever. Maybe they're tens or even hundreds of years old? But my point is that the OAS doesn't detect these tree trunks and they're proving a problem for the ROV pilots (SG - the cameras are pointing inwards to the pipelines for the inspection). I guess the logs are similar in density to water and having rounded edges they deflect away the sonar pulses rather then reflect them back to the sonar receptor.

Maybe this 'underwater mountain' was made of soft sediment and wasn't detected by sonar? It's unusual to get unidentified 'mountains' made of rock, and rock should be detected by sonar I would have thought. There are features known as mud volcanoes in the deep ocean... just a thought.


Anyway, seeing as this COP26 is currently underway, to get on the environmental topic here's a timely reminder of where your litter ends up. Right slap bang in the middle of the Black Sea, 150km from land, here was a kid's pink party balloon lying on the seabed... where it will remain forever.