Hey Guys,
I've been busy and not diving, so absent from the forum for awhile.
My first dive this year was with the SEAL group on the Sardine run.
The conditions were challenging: big swells, poor viz. There were some sardines, but not as many as I'd dreamed of.
With the poor viz, photographs were a challenge and the strobe a no-no. I tried with the 10.5 and 16, with and without magic filters, at ISO200 and 400. I think the best shots were 10.5, no filter (we were snorkeling, not diving), and ISO400. The Subal ND70 handled like a dream with no strobes and the FE port. Only complaint is that the on/off and subcommand dial controls were a bit balky.
One of my less ugly shots -- it's soft but gives a feel for the action:

Common Dolphin pursuing sardines
D70, ISO400, 10.5mm, 1/200s, f5.6; ambient.
More shots of the sardine run in a gallery ; also some post-dive safari shots .
All the best,
Chris