The premise of this thread is that a seaworthy boat of the proscribed Biblical design and dimensions is impossible. But where so many variables are involved demonstrating zero probability isn't possible, and it takes only a teeny tiny but non-zero probability to prove the premise wrong.
Believers in the Biblical stories who are of a scientific mind tend to enforce some odd constraints. They believe in miracles, but when they enter the creation/evolution debate they think that what was miraculous in the Bible must also be scientifically possible. That's why they only require that something not be scientifically impossible. Real world evidence doesn't enter into it. If it's not impossible and if the Bible said it happened, then that's what happened.
This is why this thread is full of incredible claims about the technology and shipbuilding skills of ancient Middle Eastern desert traders. It isn't impossible that Noah had access to shipbuilding technologies we're unaware of today, or that he somehow developed them himself (as well as anticipating the need for them), and this is all that creationists require to be satisfied. As far as they're concerned, the speculations they've offered are more than sufficient to have cast doubt on claims of the impossibility of the ark, and so the premise of this thread fails. If pressed, I'd be forced to agree with them.
Pushing and prodding Iano and ICANT and Peg into corners from which they're forced to make up even more fantastical proposals is where this thread is going. The more interesting discussion would be about why they're willing to entertain such wild ideas, but clearly their ideas don't seem wild to them and so this discussion could never happen.
I thought it'd be a bit of fun to dance a 'what's-eminently-feasible' dance.
It's how you decide "what's eminently feasible" that is most interesting. If in some post apocalyptic future you were one of a large group of people discussing how to preserve on a boat as much as possible of what was left of civilization with waters from global warming rising to wipe out surviving pockets of humanity, 450 foot long wooden boats would sound as ridiculous to you as they do to everyone else.
But if it's the ark of the Bible, then a 450 foot long wooden boat makes perfect sense to you.
Are you suggesting that it would be difficult to successfully construct a raft of that size? What particular technical problems do you see as insurmountable?
I'm not suggesting anything in particular about a raft or any other of the offered ideas. What is interesting is that ideas creationists would find as ridiculous as everyone else become reasonable to them if necessary for Biblical inerrancy. The discussion here isn't really an exploration of the feasibility of the ark (especially not of the ark as described in the Bible), but is instead an exercise in trying to talk creationists down to reality.
And the way to do that in the locality of a debate forum is to debate the specific issue at hand - not snipe from the sidelines.
To phrase my observation a bit differently, creationists have taken the discussion far into the realm of fantasy, turning this thread away from discussing the topic and into one of trying to get creationists to see reason. When the creationists in this discussion start debating the specific issue at hand instead of inventing fantasies then I am ready.
Concerning your specific proposal of a woven raft, if you're interested in taking discussion back into the real world then I suggest an exercise where you seek out real world examples of rafts of the scale of the ark, or of any significant scale at all. And at a minimum I suggest you persuade your fellow Christians of how faithfully this satisfies the Biblical account before pushing it here. There seems little point discussing a proposal that most Christians would reject.
To give you an an idea of the kind of information you'll find about the viability of large rafts, here are some excerpts from a 1907 New York Times article titled Big Leary Raft in Port:
The first Leary raft was launched at Joggins, N.S. in the Bay of Fundy in September, 1888. It was the largest one constructed under Mr. Murray's supervision and encountered a terrific equinoxial storm and was wrecked on the way to this city.
The second great raft, which was slightly smaller than the first, was constructed the following year, and was also wrecked in a similar September gale.
The Underwriter's tow ["Underwriter" is the name of the tugboat, "tow" is a reference to the raft's cargo] consisted of 6,000 spruce piles, and was 320 feet long, 40 feet wide amidships, and 25 feet at each end. It drew 12 feet of water.
When creationists allow discussion to be about real-world possibilities instead of fantasies, then there will be something worth discussing.
We can't say that they couldn't have built large boats until we learn more.
We can't say they weren't visited by men from Mars, either.
There's a great deal of evidence that the maximum size of wooden/reed/balsa/etc boats is limited by the nature and strength of the materials, and that the problems are made far worse if there are significant cargo carrying requirements.
There is no evidence of any boat even vaguely like the ark ever existing.
It is so easy to make the mistakes that the ancients learned to avoid.
People aren't questioning the existence of reed boats or reed houses, and they do not doubt that people would have put pitch on reed boats.
What they doubt is the possibility of extremely large multi-story structures built from reeds. Providing pictures of single-level dwellings and small boats is not supportive of that possibility. And since one would expect that ancient inscriptions would attempt to capture the most amazing structures of the day, inscriptions that do not portray anything more complex than single story reed dwellings would seem to be evidence against your position.
...[Noah's ark] is more plausible than every thing on earth coming from a singularity that has never been found or discovered, and is supposedly made of nothing, that exploded and gave us light elements such as helium and hydrogen ONLY, that over billions of years formed clouds that collapsed down on themselves to form planets and stars (without any outside energy), that in turn incomplete chemicals travelled from the surface of earth to the vents of the ocean floor to create organisms with no genetic code of any kind, and could reproduce without any protiens (that are required for all of life today to orientate, reproduce and distribute oxygen).
Let's keep the focus on the boat, but just in case you were serious I thought I'd point out that there's nothing in that paragraph that accurately represents any scientific views.
Furthermore, if this was a regional flood, mainly in the Sumerian swamps, a huge river raft that did not need to stand up to the rigors of sea travel could have been what was built.
If you're dropping the claim of a multi-deck reed boat loaded with representatives of the entire world's species then the plausibility goes way up. It becomes something that could have happened and is such an innocuous claim that there's little point to debating whether the evidence supports that it actually happened. But you now have a different problem: convincing Biblical literalists.