Best to have a couple of those spells prepared just in case then. Drowning takes place over several rounds, so you'll have time enough to cast it again if one gets dispelled.
Thanks for pointing out that the waterbreathing helm needs to change. As with the magic of a ring of nondetection no longer granting permanent immunity to scrying, expect the helm of waterbreathing to be changing sometime in the very near future as well. Most likely it will be changing to a waterbreathing spells per day model rather than a permanent "always on" model like it is now.
But if you still want a permanent always on water breathing item for your PC, my next tip is that you have it join the temple of Istishia on the Alaor or the shrine of Umberlee in Thasselen.
Thanks for pointing out that the waterbreathing helm needs to change. As with the magic of a ring of nondetection no longer granting permanent immunity to scrying, expect the helm of waterbreathing to be changing sometime in the very near future as well. Most likely it will be changing to a waterbreathing spells per day model rather than a permanent "always on" model like it is now.
But if you still want a permanent always on water breathing item for your PC, my next tip is that you have it join the temple of Istishia on the Alaor or the shrine of Umberlee in Thasselen.