I used mine in earnest exactly on a day when I thought carrying it would be an absolute waste of time. We were doing a dive in flat calm conditions at a site called "Parcel do Coronel" in the State of Rio de Janeiro, Brazil. This is a terrific site, totally submerged, made of of a collection of very large rocks so you can go down into the grooves and tunnels. I know this now because I went back a few weeks later.
Anyway we were diving off a live-aboard and it was the first trip out after some time laid-up out of service so the crew was a little rusty. Nobody on board had dived this site as on previous trips conditions did not allow.
So the boat manoeuvered in to what appeared to be a safe distance and anchored. We were at slack water minus 30 minutes. Things could not be looking better.
The group varied widely in experience, there were quite a few beginners but accompanied by DMs and instructors in a good ratio. So I and my wife jumped in to go off first by ourselves while the DMs & instructors got their groups together. After I got into the water one of the crew asked me to check the prop which I did and found the RIB tether with a few tight turns. I tried to unroll the rope turns but the problem was that the prop was just too big and the rudder too large and I ended up having to use my knife and cut through. Anyway this wasted about 10 minutes and I was starting to feel some current at the end but it was still quite light so I took a compass bearing on the marker buoy for the "Parcel" and off we went on the surface. After about 10 minutes finning in the right direction I decided it was time to have look below. Vis was about 2m! So we angled down gradually and finally hit mud bottom at about 23m maintaining our course. Carried on finning steadily and watching the air level until we hit 100Bar, still not seeing anything, so decided to surface. I found we off course, the boat was fairly small in the distance so I pulled out the buddy line to fix us together and we started finning in the direction of the boat. No sign of the other 20 divers!
After about 30 minutes finning the boat was a dot on the horizon - the current was pulling us fast away from the boat. So - time to deploy the sausage.
A passing launch eventually pulled over towards us and on board were 4 or 5 of our group that had been picked up much further downcurrent. Eventually our RIB picked us up last - we were in no hurry. Since we were the only ones that went deeper we were the least affected by the rapidly accelerating surface current after slack water.
The gratifying thing was that in the calm conditions and sunlight my sausage was visible at kilometers distance.
When we repeated the dive some weeks later I saw that we must have missed the Parcel by only 5m or so.....