Kayak with a swimmer in NH or some advice from locals

It’s a shot in the dark but I’m wondering if anyone in NH has time to kayak with a swimmer this weekend (7/7 or 7/8). I’m visiting my sister (she lives around Keene/Weare) and I’m training for a ten mile swim at the end of the month. I’d like to swim for 3-4 hours. I don’t know the area at all (this is my first time here) but was pleasantly surprised to see so many lakes!
Or if anyone knows a lake in the area that doesn’t allow boats, I could swim without worrying about being run over. I’d appreciate any help/advice.
Thank you!