[Aktungbby]

Originally Posted by Eichhörnchen

How are those exhaust ports closed off for diving the boat?

There are hand valves inside as Rhodes states. I believe the video in the OP with the heavy swirling may be a procedure necessary to the Gato diesels known as 'scavenging' a maintenance procedure to rid the cylinders of all unburned fuel That's a lot of white smoke(supercharged air) in the video not dark indicating fuel. http://maritime.org/doc/fleetsub/diesel/chap6.htm Some opinions please.