Seriously with a guarantee of no failure, I would go skydiving and deep sea diving in the Great Lakes particularly Lake Superior.
Yes, no fail jump off the plane into a field with no strong wind and sunny day. Preferably a place where the weather is warm but not too hot. Perfect landing expected because of the no fail guarantee. Would jump in a place with soft landing in a well maintained area.
My deep sea dive would be on Lake Superior to swim down and around the Edmond Fitzgerald that sank in the 1970s. My school got out when it passed by us on the Detroit River on one of its first voyages. Later on, after it sank along the shores of Michigan on Lake Superior, my school had so many students who attended both the US and Canadian memorials that it should have canceled classes. Others have tried for years to dive down to and into the freighter but weather and/or equipment failure has prevented it from happening. I would dive for my former classmates and my former Canadian neighbors across the Detroit River.
Side Note: Every dive attempt to swim down to the Edmond Fitzgerald on the bottom of Lake Superior has failed to date.
Yours Truly,
Leslie Elizabeth David.
The Magnificent Modern Mature Woman 