That looks pretty cool and handy but... consider the battery life. I have a set of Ryobi one+ power tools and their cheap batteries don't hold a charge well. And the good batteries aren't cheap but since you already have a Ryobi kit then you know the deal. It might be the case that a single battery charge won't inflate a full boat since these are meant for mattresses and pool toys.
Also consider that you can't plug it in. I ended up getting the cheap Intex rechargeable pump, https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
and the car adapter has been a life saver when the battery dies. The battery on that [with a full charge] fills my 16 foot gear boat exactly once or my mini 2-3 times. On many occasions I have had to bust out the cord at the put in - can't do that with this.
That said, you should totally give it a shot since you have the batteries. If it turns out inadequate, Home Depot has a generous return policy. If you do let us know the results.