So I had to share this because it's just so ridiculous it's funny.
My FIL is one of the nicest guys in the world, but he just really lacks a lot of common sense. He has a boat that DH and I get tons of use out of every summer. DH spent every summer growing up boating and I have the same plans for DS...when he's old enough. I am due July 8 and FIL asked if the baby would be coming on the boat this year. He insisted that DH would have as a baby except he was born in November. I thought it was just the dumbest suggestion I had ever heard, but politely responded that I think we will wait until he can hold his own head up before bringing him boating, and by that point boating season will be over, so next year is looking good. He waved it off, insisting "Oh there's been infants on that boat before!" Yeah, but not NEWBORNS!!! I just let it go knowing that I'm the mom and will not be allowing it. DH agrees with me. I mean seriously??? Why would it even be worthwhile to bring him? Someone would have to be tightly holding him the whole time not enjoying themselves. Not to mention his sensitive skin in the sun, the germs in lake water he'd be exposed to before vaccines, and of course the possibility of him falling in the water (do they even make life vests that small?) or being shaken by the movement of the boat....
I don't think he'll be babysitting with that kind of judgement.
Re: Clueless FIL
If it's a jon boat or bass boat, next year will be a maybe.
If it's large enough to have a cabin, enjoy your family time and take any other protective measure you normally would taking the baby outside in the summer.