Leg 208 began when the first line was passed ashore in Rio de Janeiro, Brazil, at 1720 hr on 6 March 2003. Incoming scientific and technical personnel encountered numerous difficulties with Brazilian immigration authorities regarding visa declarations. Most of these incidents were resolved locally with the assistance of the ship's agent. In two separate incidents involving a total of seven people, personnel were required to leave Brazil and reenter. Routine port call activities proceeded at a slow tempo. Several barge deliveries of potable water, tested for biological and chemical contamination by the ship's doctor, were needed and were released into the ship's potable water system. Frozen sediment samples from Leg 207 were kept on board because Brazilian authorities stated that it would "take a minimum of 30 days" before the specimens would be released for shipment.
The last line was released from the pier at 0721 hr on 14 March. After clearing the harbor entrance, the captain initiated turning maneuvers to evaluate the tracking ability of the very small aperture tunnel antenna. Additional personnel aboard for this acceptance test departed the vessel at 1047 hr, and the ~2500-nmi journey to the first site of Leg 208 began. The first week of the transit was characterized by a moderate southeasterly swell through which the vessel negotiated easily as it headed almost directly east to Walvis Ridge. By 18 March, the vessel had traveled 1220 nmi at an average speed slightly more than 11 kt. By the early morning of 19 March, easterly winds had increased to force 4 and eventually grew to force 6. As the sea and swell started to build, waves breaking over the bow began to inundate the bridge deck. The speed of the vessel fell below 9 kt as the vessel was pelted by rain and wind gusts exceeding 30 kt. During the evening of 22 March, the captain reduced propeller revolutions from 140 to 120 rpm to lessen vessel pitch and roll. The speed then fell below 7 kt. Later in the evening, the shafts were again back to 140 rpm as the weather gradually abated and the speed gradually increased above 8 kt.
The vessel approached the coordinates of proposed Site WALV-12A using the Global Positioning System and was on site on 24 March at 1300 hr. The 2455-nmi transit from Rio de Janeiro to the first site of Leg 208 required 239.0 hr (9.96 days) at an average speed of 10.2 kt. The corrected precision depth recorder depth was 4776.4 m relative to the top of the dual elevator stool on the rig floor, or 4776.4 meters below rig floor (mbrf). The bottom-hole assembly (BHA) (see "Operations" in the "Explanatory Notes" chapter) was made up, and all the tubulars were measured during the initial deployment of the drill string. A cleaning plug was pumped down the string to remove rust, and the slow-circulating-rate parameters were established prior to deploying the first core barrel.
Coring intervals, times, nominal recovery rates, core barrels that required drillover to be released from the sediment, and the deployments of the Advanced Piston Corer Temperature (APCT) tool, Tensor core orientation tool, and nonmagnetic core barrel are listed in Table T1.
Hole 1262A was initiated with the APC at 0340 hr on 25 March, with the bit placed at 4770 mbrf. The first core was recovered with a full barrel, and the nominal seafloor depth for Hole 1262A is therefore defined at 4770.0 mbrf (~6 m below the more accurate seafloor estimate in Hole 1262B). When the core winch operator attempted to recover Core 208-1262A-15H (133.0–142.5 mbsf), the aft coring wire parted just above the rope socket, leaving the core barrel in the outer core barrel of the BHA. The barrel was successfully recovered with the forward coring line using a "fishing assembly" made up of the lower section of an APC barrel and a rotary core barrel coring shoe. The salvaging of the core barrel required several hours, and coring subsequently advanced to 161.5 mbsf. During an attempt to recover the core barrel containing Core 208-1262A-18H from the sediment following a full stroke of the APC, one of the core barrel connections failed after the application of only 60,000 lb. The failed part was the male threaded connection between two 5-ft core barrel sections used to replace a 10-ft nonmagnetic core barrel damaged during the previous leg. The failure left most of the APC barrel (and a full core liner) at the bottom of the hole, making further coring impossible. Hole 1262A was therefore ended prematurely; the inventory of nonmagnetic APC assemblies was reduced to one.
The vessel was offset 20 m north, and Hole 1262B was initiated with the APC at 1450 hr on 26 March. In an attempt to obtain a good mudline core and a stratigraphic overlap with the initial hole, the bit was positioned at 4762 mbrf, or 8 m shallower than the initial bit position for Hole 1262A. A reliable mudline core was obtained, containing 6.91 m of nannofossil ooze. The seafloor depth inferred by the recovery of the initial core was 4764.6 mbrf, or 4753.6 meters below sea level (mbsl). Piston coring advanced without incident to the target depth of 209.9 mbsf. The bit was pulled free of the seafloor at 2125 hr on 27 March, and the vessel was offset 20 m north for Hole 1262C.
Hole 1262C was initiated at 2140 hr and drilled ahead with a wash barrel to 90 mbsf, where coring was initiated. Piston coring deepened the hole to the target depth of 212.5 mbsf. Coring in this hole was used to fill gaps in the stratigraphic record. Adjustments were made in the firing depth of Cores 208-1262C-4H (4.0-m advance), 7H (7.5-m advance), and 11H (6.5-m advance) to maintain overlaps with the previous holes.
The cored interval for the site was 493.9 m, and the recovered interval was 502.5 m (average nominal recovery = 101.7%). The total drilled interval was 90 m.
Four downhole temperature measurements (Hole 1262A: 0–143 mbsf) and one bottom water temperature measurement (Hole 1262B) with the APCT yielded an initial temperature gradient estimate of 5.3°C/100 m.
The routine recovery of the drill string was suspended for 1.5 hr for slipping and cutting of the drilling line. The beacon was recovered; the drilling equipment was secured; and the vessel proceeded to the next site at 0530 hr on 29 March.