Ok, I managed 2 dives last saturday and shoot with Canon 60mm macro lens + EF12 + 2x TC.
Conclusion? I'll never use this setup again. ;-/
Because of tube & tc, very dark viewfinder & lost many f stops.
Next time I'll try 100mm + 3x tc + diopter (still waiting ext ring for port).
except mantis, size of shrimp is less then 3~4mm((I did magnification check with ruler shot at max magnification).
I always love your pictures! I am trying to figure out what SM setup I am going to get for my canon, I have the 60mm and after doing my homework came to the conclusion that I will just invest in WA at the moment and then get a 100mm later down the road with a TC, im glad you have come to the same conclusion. I would love to see your shots with the new 100mm set up.
As for your pics I think they are fantastic, I like #1 and #3 best.