Boating with an infant and young kids now means the extra set of hands/eyes your wife provided during any and all boating tasks will now be per-occupied with child related tasks. You'll need to think about taking upon all associated tasks....launching/loading/docking/etc....
Our first year of child in the boat was my first year of figuring out how to do everything myself as I couldn't always rely upon my wife to help....sometimes there was a screaming baby that she had to tend to, other times it was "baby brain" momma not entirely focused.
Sunscreen, sunscreen, sunscreen & shade, shade, shade. The first time you burn your baby's skin from the boating outing may be the last time you ever take her out young like that as the momma will not forget and not want to risk it in the future. Trust me, you want SFP 2000 and lots of shade.
Think about your drive home. There may be times where your little baby may get motion sickness and projectiles in the car could happen. All I can say is be prepared for that. Also, know your doses for childrens ibuprofen ( or tylenol...can't remember) and have that in the car if your trip home takes time. It's possible at times they could get a headache or just not feel well from the experience and that will help ease them. I can't remember if that early of an age can take it or not, but if they can it's a good thing to have on hand.
You can never have enough plastic bags, diapers, wipes and extra clothes for you little one on the boat.
Avoid the really HOT days or if you venture out on those days make it early and don't stay out long. Stay in tune with how that baby is feeling and watch out for heat exhaustion. If your wife is breast feeding, the baby may kick up the feeding during the heat and that's good as you don't want them to get dehydrated.
It will take a couple of trips to really get comfortable with the logistics and your little one will throw some curveballs in there from time to time. We've had quite a few trips where 10 to 15 minutes after launch the baby just got too fussy and nothing was working to settle them and had to call it a day....don't let those days frustrate you it's all part of the process.
The more your out there the easier it gets. The more your out there, the more they end up LOVING IT.
Enjoy it for what it is, even if it's a quick 15 minute trip on the water. Remember, your baby feeds off of your emotions.
And as always, be safe.