Need help with pool draining

I live in NW FL and have an unground pool, that is 5' in deep end, small, approx 7k gallon pool. I live about 1/2 mile from bay water, and am at elevation of about 13'. I need to drain pool to redo gunite. I watched the pros do my neighbors and they had to find the drain below the pool to put a pump on, so the ground water around pool didn't make it implode. I assume I need to do the same thing. So my question is, do all pools put these French drain type pipes in below the pool before they behind construction? I wasn't around when my pool was originally built, so I don't know if I have a under pool drain or not. Is it customary to put a drain in? Especially in NWFL, this close to Waters edge? Where would this pipe be? Should I just start digging around the deep end, until I find it? What if I don't have one, what do I do then? Dig a 5ft trench around pool and keep it pumped until I complete repairs? Thanks in advance for the replies.

Also, how hard is it to replaster? I am rather skilled, but can't claim I ever refurbished a concrete pool