Group dynamics, family life and childrearing aboard a generational sailing fleet

Question

Background

A while back I posed a scenario of a privately owned nomadic trading fleet that sailed around the world for centuries. A commercial enterprise spanning multiple generations, without any port or shore they call their home. See that question for more background about the world and the economy. But in brief; it's a 14th-century technology and society, and geographically it looks like the Indian ocean and the lands surrounding it.

The answer I accepted laid out a very good explanation and justification for the business side of things (and you can treat that as canonical, sans the Vikings), but in the first section there are some broad statements on psychology that many people had issues with.

So rather than debate that in comments and anger some moderator, let's talk psychology here. I want to tweak or expand my scenario for realism, doing respect to the dynamics of group psychology which I am not at all an expert in, without resorting to stereotypes.

The scenario

Some fixed stipulations:

• There's a nomadic trading fleet that carries loads from port to port without calling any their home; a diverse crew made up of many ethnicities and different skillsets, that survive amidst mighty nations and pirates through the skill and knowledge acquired over the many decades of experience. They can defend themselves but they're not pirates. Don't frame challenge this part; take your concerns about economic realism to the linked question.
• There is no shore office, no home port, no village of families that is aligned with this fleet. If all the boats sink, there's nothing left of the enterprise.
• A certain fraction of the people aboard the fleet is generational: they were born and raised there and serve until they retire. This fraction cannot be 100% because then there's too many minors aboard the ship; still, my interest is in maximising it to have the highest "generational fleet" aesthetic.
• Some people born aboard the fleet leave voluntarily or are kicked off if they do not fit in. If couples on the boat generally have six children, then four can decide to leave the boat (and live with their retired relatives), so only the most suitable 30% stays aboard; hopefully contributing to social coherence.
• Similarly, hired sailors are selected for how well they can deal with this way of living. Through selection at every stage, I hope to end up with an agreeable bunch that's fine with spending a good fraction of their lives in relatively cramped spaces. The best hired sailors join the generation faction organically (by marriage).
• I don't want strict gender separation from boat to boat. It does not feel right to me. Of course some of the jobs on the fleet are going to have inherent gender bias, but I want to minimise social separation. The whole fleet should feel like one community, not two subcultures.

And here's some of my assumptions. They can be changed to make the scenario work better, but I'll give my concerns for each.

• The fleet consists of about half a dozen ships, ranging in size from yay big to yay big.
  • The ships should not be threateningly ship-of-the-line large, they should be faster and more manoeuvrable than the average warship, and if any one ship is sunk then the fleet should still have most of their wealth aboard the other vessels. On the other hand, tiny boats are no good for living, let alone raising a family.
• There's about 150-200 people in total, including children.
  • Enough to crew all the boats with some to spare, not so much that feeding them all becomes impossible on trading profits.
• They make port about once to twice a week. Smaller ships may be sent out more often.
  • This world is pretty interconnected; I think this is a valid number for how many ports there are and the distances between them.

Anything unmentioned is open for interpretation.

Question

Generally speaking, what can I do with my scenario, either by tweaking the numbers or adding stuff to it, to make it realistic from a psychological point of view? Specifically, I am interested in maximising the proportion of the sailors that's native to the fleet, maximising social coherence, subject to some constraints for ship design and population, and using selection of both native and hired personnel for coherence.

Addendum

I will divorce the available space on the ships from reality. I think designing boats that are spacious enough for childrearing is an engineering question, which is out of scope here (might use a third question for that). Let's say that space is what we would call cramped, but as filled to the brim as it was historically. For a number: every kind of ship in the KeizerHarm-universe will only require half the crew that they do on Earth. People will generally not have private cabins but there can be rooms set aside for things not essential to navigating.

Answer 1

I find the idea really fun honestly.

Round one: kid skull VS falling pulley or how to ensure nobody leaves

This part is not necessarily fully tied to psychology but it is an important point for the feasibility of your society.

Being a crewman on a ship was dangerous even for experienced marineer: illness, poor quality food, general danger of the open sea you would have a lot of losses... But with kids? Let's be nice and say mother can nurture their child with only food being found on a ship - you still have all of the high risk of medieval child bearing, but on top of that you had the extreme condition of the sea?

The amount of children they will be able to successfully raise until they are old enough to do anything will be quite low, way lower than it already was at this period in normal conditions mind you, so I don't think you can afford to only keep 30% of them especially if you want this fleet to be composed of substantial amount. You better have a culture in there that heavily emphasises how much better it is to be a sailor than earthbound.

Round two: intimawhat?

14th century ship weren't known for their luxurious life condition, sailor being stacked on top of each other in the belly of the ship and the like. It's great to have a good community spirit, but not that great if you want to get intimate with somebody, let alone form a couple. So I see two main options, either the culture there is way more open with people being just one big pile of people stacked onto each other, or you will have to dedicate some part of the ship to private life. That space would be shared by a lot of people but not at the same time. Be it the mess being reserved to courtship between bachelor at certain time of the day, and more "private" room that can be accessed and locked to actually be intimate without having to bear the sight of hundreds of crewmates.

Round 3: community

Quick aside but 200 people in the total of the fleet is just not enough. Caravel & big ship like you showed could accommodate between 50 and 80 crewmen. If you get 5 of them you are already way past your upper limit, without taking into account the small ships. Cause the bigger the community, the more chance you have that everybody will find something they like

I think to "spice up" the life on ship it would be a good idea to have each ship or ship size to have a specific social purpose. For example, smaller ships being the place where teens learn the rope of the craft.

Conclusion: the dark soul of traveling merchant In conclusion, psychology-wise it's far from unfeasible, if you can find a way for people to get a bit of time away from the big group of people. Not having an anchor point isn't that big of a deal if you have a strong enough bound between them. Your biggest problem mainly come from just how deadly the sea is as an environment.