I find a hand-held strobe very difficult, an observation reflected by Martin Edge in his new book, where he comments on the damage that the instability of divers hand-holding strobes can do to the reef. With a housing and two strobes sensible arms replace hand-holding, anyway. I have been a wide-angle aficionado, and, indeed, have only just bought a macro port after 8 years of serious photography. I use two lightweight Inon Z-220s, but often have two stops difference in power between them. A little fill often seems to be better than none at all, so I tend to use two or none, but I am often using a Nikon 10.5mm lens, which can see your feet when held to your eye! Two strobes are needed to cover the field of view.
I wouldn't suggest starting with two, though. Learn one and then add another: and don't use a slave, use two synch cords, as that's much more reliable. Get good arms, short for macro but up to 18"/45cm for fisheyes. I think that the Ultralight bouyancy arms look great, but haven't tried them yet. To get sufficient flexibility at least two points of rotation are needed, and three (two arm segments) are better. The angle at which the strobe comes off its ball joint can sometimes be awkward, as it was in the early Inon strobes which tended to project forward from the arms.
This is my sort of stuff:


Tim
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