You supply that link as a serious rebuttal to the account of a world wide deluge when the first objection is that the boat was made of wood. What natural substance would be better suited to the task? Is the author of this rebuttal even slightly aware that instructions were given to coat the wood both inside and out?
The second supposed difficulty regarding a global flood is the "problem" of gathering together those forms of life that were to be aboard the ark. This includes not only the difficulty of considerable travel from many regions involving diverse species, but also the difficulty of time since there were only seven days to load the ark.
Note that heretofore neither difficulty regarding a global flood has to do with a flood in particular, but the biblical text as it literally reads. A global flood could easily be considered whether or not there was ever an ark filled with surviving life, but the author of this article prefers to protest against more than the possibility of a flood. It is the general reliability of the biblical text that he finds repugnant (though the objection must be couched in terms of scholarly pursuit).
But what about all these critters coming from all parts of the earth? The biblical text does not denote how much time it took for all of them to come, but it does makes clear the animals came to Noah. He did not have to fetch them. Science understands to a small degree that the instincts of the animal kingdom are keen. Had science observed the animals just prior to Noah's flood, it would have put it in terms of instinctual processes not unlike the renowned march of the penguins.
If there were pending physical events about to take place on a global scale, one can reasonably surmise the instincts of the animal kingdom were accentuated. Even the recent tsunami saw isolated islands undertaking shifts in turf in anticipation of the pending disaster without expressed communication about the details.
As for the supposed problem of having too little time to get the animals loaded onto the ark, it stands to reason that the amount of potential genetic expression expended prior to the flood could have been far less than what we observe in the animal kingdom today. To put it simply, there were not as many animals needed as one might think; not as many species as we observe today.
Given the author of this article's distrust of the biblical texts in general, and his inability to know for certain the conditions under which the animals were gathered and loaded onto the ark, I do not find his second objection particularly convincing.
But of course, I am not one to question texts that have reliably stood the test of time many generations ahead of myself. I'll take the biblical texts for what they say and what they mean, and let those who believe in themselves make a mess of themselves.
The third supposed problem with a global flood again does not address the flood itself, but the supposed difficulty in fitting all the necessary creatures in the ark built by Noah as attested by the biblical texts.
In terms of modern transportation, the ark could hold a cargo similar to that of a freight train over 100 cars long. Into this space were to fit the animals that were brought to Noah, including birds, cattle, and creeping things. If one is to accept the biblical text for what it says, the animals that were gathered into the ark carried all the genetic material necessary to continue the propagation of every living thing of all flesh.
Let's suppose for the sake of argument, that the ark was to carry only two representatives of the human race, similar to the first persons denoted as Adam and Eve. These two not only represent all forms of human flesh that have ever inhabited the planet, but they carry within themselves all the machinery designed to make it happen. They wouldn't need a great deal of space. Maybe a whole freight car.
Ask any anthropologist and he will probably tell you that the forms human life has taken thoughout the generations have been exceedingly diverse, enough that human bones have been confused with those of primates. Yet out of, and subsumed in, only those two people, this entire expression of life issued forth.
One may reasonably speculate that it was not necessary to bring a sample of each form of cattle, or each form of bird, in order to preserve the flesh represented therein. The diversity was already programmed and concentrated in the creatures that appeared before Noah to be loaded into the ark.
Well, how much living flesh of how many types can fit into a 100 car freight train? Enough that one need not consider the argument a serious challenge to the biblical text when it is said it would be impossible to fit them all aboard an ark the size Noah built.