The Nauticam SMC allows the shooter to maintain a little extra working distance, allowing for some types of shots that weren't really possible before. This shot of jawfish eggs is an example.
Here is a crop of the in focus section of the eggs:
To give a sense of perspective, here is a shot without the SMC, from a similar angle but pulled back to see the jawfish in his (the egg brooders are males...) surroundings.
The Nauticam SMC-1:
These images were all shot with the Canon 70D in the Nauticam NA-70D housing.