It was mid-September 1942 when German U-boat Capt. Hans-Heinrich Giessler first spied Charleston.

Surprisingly, Giessler noted, the city was lit up and easy to find as U-455 approached from the Atlantic.

"Charleston is recognized as a bright glow on the horizon at a range of about 30 (nautical miles)," Giessler said in his diary.

Over the next two days, the ever-cautious Giessler would spread a dozen underwater mines around the harbor approaches amid hopes of blasting a merchant ship sky-high.

Still, it was the shining glimmer of Charleston, the arch of the Grace Bridge and the blinking harbor markings that stood out.

"On land, more and more lights have now come in sight, of which the most prominent are the streetlights of two high bridges over the Cooper River with their red-aircraft beacons," Giessler wrote. "The grid work can be seen clearly."

Of the Morris Island lighthouse he added: "Charleston lighthouse burns as in peacetime."

It's no secret that U-boats and U-455 visited South Carolina waters during World War II. Now a U-boat historian has recently translated Giessler's war-time ship's diary and put it online to be viewed by local residents, hoping it will expand the story of their crews, their missions and the threat they presented here.

"It really contains the thoughts of his being in command," retired U.S. Navy captain and Cold War submarine chaser Jerry Mason said of Giessler. "It's how he would be explaining his moves to his boss, Admiral (Karl) Doenitz."

2 days off Charleston

In German Navy terms, a ship's war diary is called the Kriegstagebücher, or KTB. It was the report log that all U-boat commanders would keep and provide to Doenitz when their patrol was over, detailing the weeks of cruising, successes and failures and general thoughts about defenses up and down the North American coastline.

Mason, who now lives in Victoria, British Columbia, has translated about 150 similar U-boat logs; he noted that Giessler's account details the couple days he spent lurking off Charleston, on Sept. 18 and 19, 1942.

Mason's analysis of Giessler indicates that the captain was workmanlike and cautious, without the overly aggressive nature that was seemingly desirable among most U-boat commanders.

"He wasn't flashy or flamboyant," Mason said. "But at the end of the day he brings the boat back." Giessler was 31 at the time he was off Charleston, and he survived the war.

Mostly his log comes across in sparse, unemotional terms as he notes the crew dropping mines around the harbor approaches, occasionally avoiding surface patrols.

One passage reads:

"08.45 1st mine deployed.

08.49 2nd mine deployed.

08.50 patrol vessel bearing 330°T (120° relative bearing) in sight range 1500-1800 meters.

Bow right abeam. Showed stern and came to HF (half-speed). At this moment the patrol vessel turns and becomes narrower, machine gun is ready, and is soon lost from sight to the north.

08.53 3rd mine deployed."

It also appears that most of the Charleston landmarks that Giessler records are pretty accurately identified in the log, something Mason said shouldn't be a modern-day surprise, given that many German sailors and officers made pre-war visits to the U.S., including in the merchant marine. "He knew everything," Mason said of Giessler, including the light list and chartings of the harbor.

Some success early

Mason said the recorded track indicates U-455 got to within a half-mile of the Charleston jetties, and that during the day the boat would submerge and rest in deeper water, shutting down so as not to exhaust the battery.

While U-455 was not detected during its Charleston patrol, U-boat service was considered extremely hazardous across the Atlantic. Even as the Germans experienced success in sinking Allied shipping early in the war, their victories soon ebbed. Increased use of detection devices, code-breaking and aircraft doomed their effectiveness. Of the 40,000 U-boat sailors who went to sea, nearly 30,000 did not return.

South Carolina's post-Pearl Harbor defenses did expand after being nearly nonexistent. Rick Hatcher, historian at Fort Sumter National Monument, said in addition to anti-submarine netting at the harbor, there were 90 mm cannons, machine guns and beach patrols in use. Planes also left four times a day from the Charleston area to hunt for subs.

There were at least four sightings of German subs near the harbor entrance, with the harbor closed twice due to threat of mines.

The U-455's mine-laying involved magnetic mines that measured about 7½ feet long and 21 inches in diameter, with an explosive charge of 1,276 pounds, Mason said. They were carried and dispersed from the torpedo tubes.

No ships were reported hit by U-455's mines here, Mason said, probably because the explosives were detected by the Navy during routine sweeping, or they could have been defective, as was common.

With his lack of success in Charleston, Giessler's South Carolina trip ended on a down note. After 48 hours he broke off to hunt elsewhere, pointing north for Canada. But there was some chase excitement on his way out.

"While running from the coast, a shadow comes in sight to starboard that is recognized as a steamer," his log notes say. "Because I am positioned before the bright approaching twilight horizon I can not get closer on the surface."

He ends with: "Crash dive and attempted to angle in for a submerged attack on the general course line. Steamer was estimated to be a 3500 ton ship with 4 hatches. Steamer zig zags about 90°."

He finished in disappointment: "Pursuit broken off as hopeless."

Mason's full translation of Giessler's log can be viewed at http://uboatarchive.net/KTB455-4.htm

Reach Schuyler Kropf at 937-5551