Actually, the tides were pretty high that entire week and pretty swift as well. I'm a Marine Biology student and I work in that field as an intern currently, so I pay quite a bit of attention to the tides on an almost daily basis. I also drive from Long Beach to Stennis several times a week and travel down Hwy. 90 to avoid I-10, so my route takes me from Long Beach, thru Bay St. Louis, Waveland and on to Stennis. This is also an often traveled route to NOLA from this area. This is one of the reasons I feel it's very probable they drove to this area, because of the locations of the remains found along this route.
With the tides moving so swiftly that week, it's not unreasonable to expect that if they made multiple dumps, perhaps at the end of a pier for example, the remains would've washed up quickly on the shore or near shore and would've been at least partially buried in sediment brought in from the tides.
Multiple dumps would also explain why the torso was found Thursday evening and then just a few miles east a few other parts were found in a concentrated area in Pass Christian on Saturday morning (near other piers, marinas, construction area) as well as her head being found in Long Beach, just a hop, skip, and a jump away. I wouldn't even be surprised if the dumps were made on separate days while the killer(s) kept up with where the searches and discoveries were occurring via media.
If they have consulted with the Oceanographers at USM--these guys are good at what they do. This consultation seems to have shifted the suspected dump site to Mississippi. So I personally think it's possible the murderer(s) made dumps here---perhaps in an effort to distance themselves from the crime, instead of dumping closer to home? I have no doubt that whoever did this did not think her remains would be found and identified so quickly and was not banking on the attention the case has gotten--therefore it seems they made a lot of mistakes in covering their tracks this time--they got a lot of unexpected wrenches thrown in their plan.
Or it could be that she did come in from the west via the currents. Like I said, we don't really know enough at this point to rule anything out. I just want the truth for this precious young lady that was lost and for justice to be served. At this point, it's all speculation.