Hurricanes and wreck movement/damage

[RickI]

First, I want to wish everyone in the path of Earl the best of luck and as little impact as possible. It is never any fun to have a hurricane path projected anywhere near you.

Looking at Earl, it seems like the leading right hand quadrant of the storm is aimed around OBX by the forecast for about three days. It is supposed to veer off to the NE before striking which I certainly hope happens. This may set up some strong deep water waves. Earl is supposed to be a Cat. 3 storm perhaps even up to Cat. 4 within this interval. This was similar to the circumstances of Hurricane Dennis which ended up shifting and righting the Speigel Grove off Key Largo in 2005. There was some confinement of water flow in the Straits of Florida unlike up your way. In the hurricanes of 2004 and 2005 we had some deep wrecks like the Lowrance in 240 ft. of water moved a couple of hundred feet. The Mercedes sitting in shallower water was also moved and suffered some damage. I recall seeing a paper prepared by a diving meteorologist written out of interest documenting how Hurricane Andrew smashed a bunch of Dade County wrecks to plate.

So, how common is movement of your deeper wrecks and damage following hurricanes off the OBX particularly on your deeper wrecks, say below 100 ft.? I was curious if you will see any thing like this following Earl.

Again, best of luck with Earl and any other tropical system that blow through this season. These same factors that contribute to major underwater forces can also generate some substantial storm surge so take care.

 

[Drewski]

Well, most of our wrecks have stuck in place for more than 65 years and weathered a bunch of hurricanes.

Most of the wrecks you mentioned were "artificials" with minimal settlement. I.e., they are not "stuck" to the bottom.

Most damage to wrecks from storms off NC are collapse of bulkheads and minor movement or collapse of other structures. I'd be amazed if a wreck actually "moved," although that clearly has happened to more recent wrecks in Florida.

 

[diveonthefive]

When Hurricanes Fran and Bertha came through, they tore the Aeolus into 4 pieces, rearranged the wreck, and righted the stern section.

 

[Akyla]

Drewski is correct about why the Hatteras area wrecks are generally not moved in location. However, we do see alteration of the wrecks due to storm action and sometimes it can be significant.

I was diving the Proteus two weeks ago when the swell from the first storm of this Hurricaine season was arriving. At 110 feet you could feel the effect of the long period swell, there was a surge that moved you a foot or so as each swell passed. There is a lot of energy in the big swell and it claws down deep.

Most of the storm damage occurs to the sites in less than 100 ft of water. A good example of this can be seen on the British Splendour. This tanker wreck is sitting turtled and is now in the process of collapse. One of the big storms several years back (name eludes me as they all seem to blend together after a while) came close by us and created big swell conditions. Next time I dived the Splendour several of the hull plates had been torn loose and bent completely back upon themsleves and the hull was cracked open. This allowed the wreck to settle a bit and the crack is now about ten foot wide.

Time and storm damage makes them change over the years. There is no stopping it and all wrecks in the reach of big wave action end up flattening in time. Even those in the deep cannot defy the forces of the corrosive ocean and gravity forever.

Dive them while you can...

 

[RickI]

Thank you for the input. The bathymetry is different up your way, no Florida Straits confinement, still long period deep water waves in shoaling conditions will do similar things to a degree you would think. Thanks for mentioning the Aeolus sunk in 1988, I found the following description:

It's intact nature made it popular to many divers because "it looked like a ship". This all changed in 1996 with the arrival of Hurricane Fran. In an amazing testimony of the power of wind and ocean, the storm took the 446 ft ship which had been sitting in intact, in over 100 feet of water , buried 20+ feet into the sand and started rocking it in the swell. The rocking continued until the entire ship had been torn into 3 major pieces and turned right side up and 90 degrees to where it previously lay. What was once an intact ship had been blasted apart. Today, the Aeolus looks like what more typically looks like a NC wreck. It covers a large area and the parts are scattered, making no "functional" sense as they sit on the ocean bottom.
http://www.nc-wreckdiving.com/WRECKS/AEOLUS/AEOLUS.HTML

It is interesting that someone observed the rocking. Also, it was embedded 20 ft. into the bottom. I will have to ask the guys in the Keys if they noticed any rocking with the Speigel. Hurricane Dennis passed 200 miles away so there could have been someone on the wreck around that time. I suspect there was no one out on the wrecks observing things during Andrew in Miami-Dade or Broward Counties as it passed over!

Your comments about the surge are interesting as well. I was speaking to some West Palm Beach dive boat operators about conditions for diving this weekend. They said Hurricane Earl, even though hundreds of miles to the east of the Bahamas had sent in some long period swells that created a strong bottom surge around 100 ft. of water. This would cause divers to sway back and forth a good distance and reduced visibility to around 20 ft. where it usually might be 50 to 100 ft. or more. Further south off Ft. Lauderdale visibility was 100 ft. at times this weekend well in the lee of the Bahamian Plateau from the storm swells. With other storm setups we get strong swells through this area anyway, just not with Earl in the Ft. Lauderdale area compared to points further north.

We have tons of old accidental wrecks in SE Florida but many are in more shallow water where they struck a reef or intentionally grounded after a torpedo strike. Most of those were blasted to plate long ago to reduce hazards posed to navigagtion. So it is hard to say what additional damage hurricanes have done to them along with movements that may have happened. The wave/current loadable vertical surface area is minimal at this point. There are some accidental deep water wrecks too but I don't recall hearing much about hurricane impacts on them.

I am glad Earl wasn't as bad as it might have been up your way. If you notice hurricane related changes on some of your wrecks it would be good to hear about them. Good luck to all of us through the hurricane season.