Water-salvaged material is not automatically metal-free. Many logs have old spikes in them, or parts of chains and other material used to originally haul the logs around. Care has to be taken to remove the metal before sawing.
Logs that have spent decades underwater often display a myriad of unusual colors—not just blue stain, but a range of mineral stain can make this product range in shades of blue, black, purple and many other colors. Some material pulled from saltier water even shows green and yellow and reds.
Engineered wood flooring is definitely the best alternative for the hardwood flooring and you cannot find a better alternative for this than the engineered wood flooring. They are unique in their technology and the way they are being installed.