...and don't worry about 4 secs 'till you start racing; at which time you'll either be in a class, against other P16's, or in a handicapped fleet of many boats, and whatever limitations your boat might have will be factored in.
Meanwhile, do like Rick says, Roll-tack from the beginning. You'll find your pleasure sailing more pleasurable. Oh, not having boards isn't too problematical, when you get your weight aft, elevating the bows, your boat will just pivot "on its heels".
Question for the experts out there: Spent the day in 20-30mph on a H16. We were carefull to not let it pop a wheelie during tacking. Do P16's pop wheelies in heavy-air tacking? Might be a factor in your heavy air roll tack.....