Add a SS 3-step telescoping ladder to the stern. Put it high and zero holes below the waterline, just make sure to insulate the tin from the SS bracket and fasteners.
Here's one for only $46! Or search eBay for '3 step telescoping ladder'.
https://www.ebay.com/itm/3-Step-Boat-Stainless-Steel-Telescoping-Ladder-Swim-Upper-Platform-Marine-Yacht/173233632245?epid=23007871789&hash=item28558773f5:giIAAOSwQcJaOiRk:rk:1f:0
You can see my friend added a simple looped bungee (top left) to keep it collapsed, plus there was a 'notch' that held it up when not in use. Pretty slick!
Here's one for only $46! Or search eBay for '3 step telescoping ladder'.
https://www.ebay.com/itm/3-Step-Boat-Stainless-Steel-Telescoping-Ladder-Swim-Upper-Platform-Marine-Yacht/173233632245?epid=23007871789&hash=item28558773f5:giIAAOSwQcJaOiRk:rk:1f:0
You can see my friend added a simple looped bungee (top left) to keep it collapsed, plus there was a 'notch' that held it up when not in use. Pretty slick!