Need advice: Is Drifting without power safe outside?? (Off Fire Island Inlet)

Hey Guys, Relatively new to boating/fishing and loving the heck out of it/can't get enough.
Want to get outside to catch a doormat (or at least a keeper we can eat!) before the season closes. I have a 17 foot Whaler Montauk with a 90 hp. I took her directly south of the fire island inlet last friday into about 50 feet of water, just to try it out, I would say there was about a 3-4 foot swell that was fun to operate in, she is very seaworthy for her size and the engine although sometimes a little cranky when it starts (sometimes it takes a few tries) has been running like a champ once it gets going. My question...is it safe to turn the motor off to drift for fluke in the ocean? (I have been doing this inside)
I read an article that you can suddenly get hit with the wakes of ships from miles away and that these wakes are huge and can swamp a smaller boat like mine. I'm thinking that if I already had her running, I could turn into this wave and drive over it instead of getting pooped over the transom. I took a large wave/wake over the transom near the channel while in the shallows by sexton island off ocean beach a few weeks ago. I had about 6 inches of water from midship to the stern inside the boat and the bilge pump got rid of it pretty quickly, my concern is that this could happen in a much bigger way in the ocean and be a problem. It is much more pleasant to drift/fish without the motor running, but is it safe in a boat my size???