Trojan Odyssey - Clive Cussler

There is a brown tide infesting the ocean off the shore of Nicaragua. The twins are working in a NUMA(r) underwater enclosure, trying to determine its origin, when two startling things happen: Summer discovers an artifact, something strange and beautiful and ancient; and the worst storm in years boils up out of the sky, heading straight not only for them but also for a luxurious floating resort hotel square in its path.