I know Aransas Bay waters quite well being in the Coast Guard. The deepest water you will find out of the ICW is about 8ft. I would guess the 6ft would suffice. I would email the company and ask them...I have checked out their website and they can definitely answer the depth question for you.
Being a man of the water and a fisherman with a boat that does not have a Powerpole, I would push you to get one. I can't tell you how many times I have come up on fish and tried to lower the anchor to hold station and scared everything away.
I have also fished on boats with Powerpoles and almost spent more time oogling over how amazing the ease of a Powerpole is than fishing!!
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Fish on!