[It's... not quite what he was expecting either. When he'd seen a spell called Mer's Lungs he had interpreted it as more metaphorical than one tat literally gives the caster gills. Wincing, he lowers his hand- in spite of the stinging, there's no blood.]

... supposedly until "the next dawn".

[As Berserker noses at him, Diarmuid tilts his head, letting him get a better look. It's a strange sight and not a particularly attractive one either but it's only temporary and he has enough faith in his abilities to be certain there won't be permanent damage. As for whether he can try it again...

A little unsteady, he catches himself on Berserker.]

Give me a little while. I think I underestimated how much it would take out of me... [He smiles weakly.] Besides, I want to see if it actually works.

[He tugs his cape off and sets it down alongside Gáe Bolg, his tunic following a few moments later. Then, a little uncertain, he wades out into the water- and gives a little gasp of surprise.]

You didn't tell me how cold it was...!