i'd say its pretty specific...

i used to wander around spinning poles and hammers as i worked to helpwith wrist strength but i dont know how effective it was.

i've seen hammer style wrist curls used to target uwh muscles.

yeah i guess one-armed rows might be a good one? i'd hold the dumbell so its lined up across your body to make it more specific and keep the angle closer to what you'd have in the water.

__________________
it's more polite on the grating than on the subs bench