Can I fly near a seaplane base?

I want to fly my Mavic over a lake, but I see I'm about 5.5 miles from a nearby seaplane bass. According to UAV Forecast it's not a NFZ...do I need to worry about accidentally landing in the lake should I get near that 5 mile radius?

To be clear, I'm not asking to break regulations, I just want to know if my Mavic will autoland in the lake if I get close to that radius or accidentally fly within it.