With 110-volt power used by private home owners for powering their boat lift, or a boat marina with 110-v dock outlets, there is the potential for someone swimming nearby to experience the shock from stray voltage loss into the lake water which can cause a drowning.
Amazon has a $99.99 Shock-Alarm-electric shock drowning protection for pools, boats, & marinas that gets a 4-star rating and has 93 user opinions.
www.shockalarm.com ..... $99.99 ......
https://youtube.com/watch?v=e5bf7X7OyCc
www.shockalert.com ..... $149.95 ......
https://www.youtube.com/watch?v=jhXUR63BEhw ..... This Shock Alert, a floating yellow device that beeps and lights up is attached to a short tow line, and seems easier to use for testing marina or town docks which are a much larger than a private dock.
Have never, ever seen anyone use one of these in Lake Winnipesaukee?
Anyone have any experience using it?
Anyone have any experience with getting shocked in the water and was it a shocking experience .... ha-ha-ha ...

... sorry, couldn't resist that wisecrack on what is a serious safety issue. ....
Is NO joke .....
https://www.electrocuted.com/electrocution-in-water/ ...... some information, here, from the friendly & experienced Electrocution Lawyers in Farmington Hills, Michigan (not a joke-

). ... ho-ho-ho! ... eek! ... budda-bing! ... zap!