One of the yachts my wife and I did our sail training oon carried a similar
ladder as part of its kit, even though our club (and theirs) was amptly equiped with such for boat work.
At one point we all arrived exhausted at about 10pm to the Queenscliffe seawall, and the only spot available was sheer concrete walls about 12 feet above the deck.... The skipper set up the
ladder, had two of us hold it while he went up, short chain and padlock attached it to a top ring and secured it for our use.
On another occassion when needing to stock the boat for the Melb/Hobart race, the
ladder became a gangplank, with a wooden plank laid atop it. This facilitated easy tranfer of sails and supplies while tied up to a less then stellar dock.
I beileve the skipper also mentioned that if the crap was really hitting the fan, that
ladder was part of his sea-anchour / drogue plan.
I have never known the man to carry excess nonsense on board (except for some of his choces in crew) and thoguh we certainly do not carry one on my boat, he seemed to arrive at the ocnclusion that it was a good idea.
Sasha