Interestingly probably not. And I'm answering from first hand experience.
While a toddler I was taking a bath at home. Mom had taken down the blinds in the bathroom and the curtain rod was sitting atop the toilet lid, which was next to the tub I was in.
Just beyond the toilet sat an electric space heater. Its heating element was glowing red hot. I noticed all this.
Being bored I reached over and picked up the metal curtain rod. Then without further thought I poked the red hot heating element of the space heater with the rod.
It felt like a hundred hands kneading my arm causing the muscles to pulsate. I quickly dropped the rod back onto the toilet lid and just sat there in the tub water up to my chest.
And there you are. I lived through an electrocution where the current was probably higher than a taser would have. Why?
Now that I'm a graduate physicist I know why. The current coursing from the heating element and through my arm was looking for the path of least resistance to flow through. And while my arm was above the water line in the tub, that path was through my arm.
But when the current reached the water high on my chest, the water became that path of least resistance. So the current left my body from a point high on my chest and then went through the water. And still seeking that path of least resistance, it found the drain pipe that led to the ground where the current dissipated.
In other words, that current never went into my heart where it would have certainly killed me. Had I been sitting in an empty tub, I wouldn't be writing this answer today.
So if you are up to your neck in water. That taser current will by-pass your body and go into the water, which is the path of least resistance. And other than a burn on the skin where you tased yourself you'll be no worse for wear. ANS.