I really like your scenario of a Punic civilization surviving in the western hemisphere. Let me divide up your post to offer questions and comments.
stevep said:
Given that the Carthaginians were renowned traders and sailors could they have adopted to oceanic conditions? I.e. basically have developed some form of sailing ships that would have been more seaworthy in open waters. This would also have cut the sizes of crews and hence made such trips easier and cargo capacities larger. Not sure if all ships at the time were rowed. Warships generally were but large bulk vessels, like the great grain carriers that eventually brought Rome its corn probably weren't.
Do you know specifically when Cartheginians or other Phoenicians would have introduced unrowed sailing ships? It would be useful to me as I'm in the process of writing a novel set in the 8th century BCE, I have a rather eccentric merchant captain (born in Akko, raised in Dor, and educated at a maritime academy in Tyre) who needs to be cut off from Israel for several years. I'm thinking of sending him across the ocean or a least around Africa, from the Red Sea to the Pillars of Hercules (which I assume the phoenicians knew by a different name - do you happen to know?). I've been assuming the ships of my character's latest fleet would have their usual oars plus one rectagular sail, perhaps with an innovation, the foresail added, an extra sail added to the bow. Shall I have them reduce the number of oars (or increase the size and displacement of the ships without increasing the number of oars) thus increasing the cargo volume but still providing backup propulsion for times when the winds are not favorable? I suppose there is no evidence to prove that such an innovation did not occur as our only way of knowning about their ships come from the few that have been excavated as well as the drawings on pottery. What I think places provides my character with a need for more "sea worthy" ships is his assignment to lead a fleet across the length of the Red Sea, to the southern tip of Arabia, the Red Sea being less friendly to ships than the calmer Mediterranean.
stevep said:
The colony, established wherever you like likely - or prefer - struggles at 1st because of its small size and limited resources. However it will have metal technology...
OK, here we need to consider how they're going to:
1) maintain a supply of the metals that they need - this requires that they either discover places to mine iron, copper, tin ore, etc in the western hemisphere, or that they can purchase smelted metals in the east and take them to their new colony.
2) that they have enough people in their colony to have a metal working class to build and operate forges
I would propose for your scenario a transitional period where during the time that they still have contact with the east they build up a self-sufficient metal industry in the west. So we have to find out about sources of ore and choose the location of the colony appropriately.
stevep said:
...large ships to enable trade, horses and probably other bits of knowledge. [For instance I don't think the Americas had much in the way of writing at the time. That would be a big advantage to the settlers, enabling them to keep details and gather knowledge and make them look even more like magicians to the natives].
yes and to transport horses they need pretty large ships, although I suppose they already moved horses shorter distances by sea as early as the LBA.
stevep said:
Also there is disease, although not sure how many of the plagues that devastated the region after Columbus were already around in Hannibel's time.
Yeh, I'm not sure either, but as a medical doctor I should look into this. I can tell you that plagues don't depend only on having a microbial agent and a vector if needed, but on the environmental conditions.
Yersenia pestes (check spelling, I may have it wrong), for instance, which caused boubonic plague in Europe had come from Asia and was particularly bad in Europe because the unsanitary conditions allowed it to spread in rats, I think.
stevep said:
Over centuries they establish a state, gradually either conquering or intermarrying with the locals. [Probably a bit of both]. Either they send secret missions back to the old world or, because they fear discover or during the difficult early years they lose the knowledge/resources for oceanic travel. Either way they have some history, which might make them hostile to anyone from Europe. [Especially since the language of the highly educated and any priests in a ship from Europe will be Latin!
]
Actually the punic language was effectively Hebrew although the writing was ancient Hebrew while the characters that ultimately were used in the Hebrew of the tanak came from Aramaic. To study their bible, some priests had reading knowledge of Hebrew but certainly they would not understand the ancient letters that the carthgineans would still be using (or some derrivative of them). But the talking would be Hebrew and would correspond to some words that the priests might consider holy. It might scare the crap out of them. Even more to the point the cartheginians in American might have preserved alternative --and much more pagan oriented--versions of some of the stories that ultimately got into the tanak and the christian bible.
stevep said:
Therefore when Columbus arrives he might find a markedly more advanced culture.
Steve
Perhaps more advanced than Columbus' own people. Being cut off from the Mediterranean in Roman times, the Carthegineans in America would be starting off with the knowldege of the Greeks as well as Roman level technology. While Europe is going into a dark age the Punic colony might advance considerably. Suppose they were in Central America, where from the Mayans they learn the concept of the number zero and also develop steam power in the early in the common era. If this happens they might have steam ships even before the fall of the western Roman Empire. By the time of the beginning of Islam in the east, the punic colony in America might be developing aviation and electricity. I suppose by that time they would be an empire in north and south america and probably interferring with activities on the other side of the globe, such that history would have been entirely different and there would be no columbus and perhaps no viking explorers. Or perhaps the innovations I proposed would take longer, such that the punic-americans would receive the arriving europeans arund columbus' time , but still be more advanced. Perhaps having a small population they would leave europe alone and watch them develop from the skies and through spy networks, and thus be tracking the european explorers, and receive thier first ships saying, "Welcome. We've been expecting you. The passage that you seek lies hither. We call it the Panama Canal."