Big 'O' double header trip report

[Wookie]

It’s a boat captain’s dream. The boat was almost sold out, but only 7 divers showed up to take advantage of the diving. 11 crew and 7 passengers left from Joe Patti’s Seafood House to dive the USS Oriskany and the USS Ozark off of Pensacola, FL on Thursday evening. The weather for-cast was not optimistic, but we are a group of hairy-chested deep sea divers, and we weren’t going to let a few waves stand in our way. Until we went out the pass. The wind was out of the Southeast, and the tide was ebbing. The tide in Pensacola Bay is only 6 inches, but Pensacola bay is huge, so a 6 inch change over a few hundred square miles is a lot of water flowing out the pass. All that water was piling up in the pass making our transit out the pass slightly lumpy. As in, everyone woke up.

We set a mooring on the Oriskany about 100 feet towards the stern from the island. The mooring was on the edge of the flight deck, and very near an elevator. Conditions on the first day were: seas 3-5, wind 15 SE, vis 40 feet on the bottom, varying towards the surface, and water temp was 71 on the flight deck, 86 on the surface.

Let me tell you my impression of the Oriskany. This wreck is not diver friendly. First of all, it is deep. The flight deck varies from 145 to 155 feet deep, and is about as interesting as diving in the sand. It is literally covered with very small sea urchins and bristle worms, with a few octopus holes and a moray eel or two. For only having been down a few years, it’s starting to fall apart, and deep penetration is unwise. There are large holes in the deck where the plating has fallen through, allowing for easy diver penetration where recreational divers were never intended to go. Parts of the island have collapsed on the deck, creating a danger for divers penetrating the island. For me, the Oriskany is a once in a lifetime, “been there, done that, got the t-shirt” dive, or an excellent place to teach trimix classes. As far as recreational diving goes, I’ll take the Vandenberg any day.

On Saturday the waves had settled somewhat, to 2 to 4’s, but squalls kept blowing through. 2 more dives were completed on the Oriskany, everyone choose to enjoy a frosty beverage rather than partake in a night dive. On Sunday morning, we got up early, pulled the mooring, and headed off to the Ozark. The divers with me came to dive the Ozark. We spent 2 days on the Oriskany warming up, getting rebreathers working, testing cameras, and we felt ready for this dive. The Ozark sits in 330 feet of water, with the deck at 300 feet, and the helo pad at about 260.

The Ozark has an interesting history (with many thanks to Mike Barnette for providing it for us). It was a target for the Air Force in the early ‘70’s. She broke free of her anchorage and washed up on the beach in Destin, FL during a storm. The Navy spent oodles of dough towing her back to the target area, where the Air Force eventually hit her (after many attempts), sinking her with a single practice bomb. She sits upright in 330 feet of water, with the crow’s nest at 220 feet.

The shot line landed on the main deck in 240 feet, and the mates tied in the shot line for the rest of the divers to jump. Divers did between 15-25 minutes of bottom time, and headed back to the surface. Vis on the wreck was 100 or so feet, and there was no current.

As usual, a great time was had by all, including the crew.

Frank Wasson
Patti’s Seafood Dock
Pensacola, FL

 

[TSandM]

Interesting review of the Oriskany as a dive site; I will share the link with my husband, who has seriously wanted to dive it.

 

[shoredivr]

For only having been down a few years, it’s starting to fall apart, and deep penetration is unwise. There are large holes in the deck where the plating has fallen through, allowing for easy diver penetration where recreational divers were never intended to go. Parts of the island have collapsed on the deck, creating a danger for divers penetrating the island.

Falling apart more than you would expect? I'm used to Great Lakes wrecks, they tend to hold up because of the cold fresh water.

 

[Wookie]

More than I would have expected after being down less than 10 years, but that is the way of the ocean. I'm more used to wrecks like the Spiegel Grove which is in relatively good shape after being down since 99, and tossed about by hurricanes.

I guess I touched a bit of a nerve by my trip report. I am a diver of reefs and pretty fishes, even if the reef is 300 feet deep. I like historical shipwrecks, and am not a true fan of artificial reefs. I find the Oriskany to be about as exciting as a parking lot, because that is where I spent my time, up on the deck. The holes I peered in had wiring hanging as well as pipes that had come loose from their hangers. For the folks who are interested in the history of the Oriskany, for deep technical wreck divers who need a place to practice and get further certifications, and for those who need a place to get to the sand in 212 feet, the Oriskany is the place for you. It isn't the place for me. We will continue to run charters here, because folks are into the wreck. I will continue to sit on the boat and help tech divers out of the water, because it isn't my cup of tea. For those I insulted by my description, hey, it's just a wreck. I didn't insult your mother....

 

[DA Aquamaster]

The Essex class carriers were perhaps some of the best money the US Navy ever spent in terms of getting 20 to 40 year careers out of wartime built carriers through SCB-27A, SCB-27C, and SCB125 and 125A modernizations. But it pressed the basic design past its limit and top weight was always a concern, although not to the same degree as in the more heavily modernized and expanded Midway class carriers. The end result was that heavier internal equipment, angled decks and internal changes pushed the displacement up about 20% and required substantial blisters on the hull to provide stability, increasing the beam of the hull by about 8 ft in the SCB-27A/SCB-125 ships and about 10 ft in the SCB-27C/SCB-125 ships.

In the Essex class much of the plating on the taller redesigned island of the modifiied ships was more fairing than structural, especially due to weight concerns, so early collapse is not surprising. Same with the deck plating. The original decking in the class was primarily wood, eventually covered with non-skid material with the Oriskany being the exception where part of the flight deck plating was replaced with aluminum plate as part of the SCB-125A modification. A factor here is also that the original steel deck plating was covered by teak planking and nonskid and as such was much better protectred from the elements than it is now, as the wood planking was removed as part of the PCB removal and general cleanup process.

Something to consider here too is that in all the US pre-war/WWII carriers, the hangar deck was the main deck and everything above it was superstructure and in relative terms, fairly lightly constructed. In the Essex class the hangar deck is the main deck with nothing above being either very heavy or armoured. That makes it distinctly different than most other WWII naval vessels where the weather deck is in fact the main deck and more heavily constructed and in some cases armoured.

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The SCB-27A mods were primarily designed to allow the ships to operate heavier aircraft utilizing the H-8 hydraulic catapult, stronger flight decks and some internal re-organization based on combat experience in WWII such as relocating the ready rooms from the gallery deck to below the 1.5" armoured main deck (hangar deck). This still resulted in some significant limitations in terms of jet aircraft operations.

The unmodified Essex class carriers when used in korea with early jet aircraft could only spend about 2 days on line before having to replenish fuel and munitions. Aviation fuel capacity was limited to about 150,000 gallons and was limited to a single grade of fuel. Given that both piston engine aircraft such as the F4U Cosrair, AD Skyraider and COD and ASW versions of the older TBF/TBM Avenger were used as well as early jet aircraft such as the F9F Panther and F2H Banshee, this meant the jet aircraft were forced to use 100/130 grade aviation gasoline with a lubricating oil manually blended into it. The use of avgas in the jet engines resulted in higher combustion temps and shorter engine life on already short lived early jet engines, and even with the added lubricating oil, fuel control unit failures were common and would often result in a flame out. The SCB-27A mod increased intenral aviation fuel capacity to 300,000 gallons but it was still a single grade fuel system.

Some of those deficiencies were further addressed in the SCB-27C mods when stronger C-11 steam catapults were added along with an automatic fuel blending system and higher pumping capacity. However, the main purpose of the 27C program was to accommodate the use of nuclear weapons and most of the mods were driven by that goal - stronger catapults and heavier arresting gear intended for the heavier aircraft needed to carry nuclear weapons along with substantial internal arrangement to accommodate the storage, assembly and transport of nuclear weapons aboard ship. That has gotten downplayed in most histories of the class.

The SCB-125 mod incorporated the 9 degree angled deck and enclosed hurricane bow mods to what were originally straight decked carriers and was applied concurrently to the last few 27C mods and retrofitted in a second refit to the earlier 27C conversions.

The SCB-125A mod applied only to the Oriskany. The Oriskany, not completed by the end of WWII, had been completed in 1950 to the SCB-27A standard and served as the prototype for that modification. It was then the last ship to receive the angled deck mod in 1957 and received a more extensive conversion than the average SCB-125 and was the only SCB-27A ship to be retrofitted with hydraulic catapults. The intent was again to serve as a prototype for further Essex modernization, but the Navy never pursued it beyond the Oriskany as by then it was already evident the class was too small to efficiently operate the next generation of jet aircraft, noteably the F-4 Phantom.

It's completion and modification history make the Oriskany very unique, but like the rest of the class, its basic construction leaves it vulnerable to fairly substantial decay above the main deck as an artificial reef so it will be interesting to see how well it fares over time.

I suspect it will continue to get less friendly but perhaps more interesting in terms of penetration, and the decay of the superstructure should make it more fish friendly and increase the appeal to the pretty fish divers, although the flight deck will always be a it too deep for recreational diving purposes. And I suspect it will contuinue to settle deeper into what is a comparatively soft bottom when you are talking about supporting a 40,000 ton carrier.

Nothing against Pensacola, but there were better places to put it where it could have been sunk that would have made it both more accessible and a bit shallower without creating a navigation hazard - but it no doubt improves the fishing off Pensacola.