We took a Labrador with us to the Marquesas. Dog grew up on land and was introduced to the boat when she was about 3 years old. Had a battle getting her to do her business on the boat. Finally just took off on a short cruise and kept her on board. After three days she finally couldn't hold it anymore and went on the deck. We gave her lots of praise and affection when she did it and everything was fine thereafter. She'd dump on the deck and we'd just scoop it overboard and clean up with salt salt water, No problem.

We had a Westsail which has a pretty tall companionway ladder. We initially would give her a boost up the ladder to get her on deck and she pretty much jumped down. In a short while, she learned to get up the ladder by herself at anchor but needed help at sea. Mainly just keeping her from getting thrown sideways off the ladder by wave action. She +pretty much hung out in the cockpit during the day while sailing. She would move around on deck but her paws really weren't very good deck shoes so she slid around a lot when conditions were challenging. She'd come down below at night and sleep on the cabin sole.

Unfortunately, we let her ashore on what we thought was a deserted bay early on in the Marquesas. A local dog showed up and she went romping around with it. It was only a few minutes but long enough for her to pick a before then unknown form of distemper. A little while after that, she got sick and died. There was a research veterenarian from Scotland in the anchorage and he did an autopsy and discovered what had killed her.