Not with their lungs. At no point in the evolutionary development of human beings were lungs an organ capable of performing gas exchange with water.
Aside from the structural changes necessary to make lungs process water being practically impossible, there's no way the surface area of lungs could process enough water to provide the oxygen necessary for human metabolism.
You'd first have to engineer novel mutations that produced huge flaps of skin extensions, then refine them into membranes that can act as gills underwater while being capable of folding up into pouches to prevent catastrophic dehydration in air.
Not with their lungs. At no point in the evolutionary development of human beings were lungs an organ capable of performing gas exchange with water.
Aside from the structural changes necessary to make lungs process water being practically impossible, there's no way the surface area of lungs could process enough water to provide the oxygen necessary for human metabolism.
You'd first have to engineer novel mutations that produced huge flaps of skin extensions, then refine them into membranes that can act as gills underwater while being capable of folding up into pouches to prevent catastrophic dehydration in air.