With the added input it I say it depends on the vision for the cruise/trip. If it's dive centeric then I'd say for them to do a discover dive at home and if they like the experience get trained pre-trip. Remember that not everyone's first time(s) on scuba is a stress free lark. If nothing else get them out skin divng a bunch pre-trip. Make sure they are comfortable in the water, used to sustained oral only breathing and having their faces in the water. These things will go along way towards derisking the adventure.
If diving is just something they want to try as part of the trip then Perhaps start slow at one port with a discover program and if they prove to be easy learners a resort course/dive at the next port will bring them further along. As mentioned these are all terminal programs with no credit or certification.
Pete
If diving is just something they want to try as part of the trip then Perhaps start slow at one port with a discover program and if they prove to be easy learners a resort course/dive at the next port will bring them further along. As mentioned these are all terminal programs with no credit or certification.
Pete