Well, there is offshore and being way offshore in the middle of nowhere.
Frank did voyages across the North Sea to Norway and Denmark with no expectations of quick help if things went wrong.
As such, he would have to cater for all eventualities as best he could.
In a storm force 9, it would be essential to be tied to the dinghy.
Being permanently lost overboard is the alternative.
Let’s face it, he was sailing at the edge of survival conditions.
Great seamanship, not sure I would want to even try.