The phrase "to walk the plank" means forcing someone to walk off a wooden board into the water, often as a punishment or a form of execution, particularly associated with pirates. Full definition
Oh and it's easily accessible by boat too, so there's no need to walk the plank at the end of your stay. (idealhome.co.uk)
The vulnerability is common, and it will cause other service - based companies to walk the plank of public outrage if it is not properly understood and contained. (inc.com)
An example of this would be activating as many core muscles as possible by performing a lateral walking plank. (sportstarsmag.com)