Across the Weddell ice field...

We had been asleep when the Orion had first steamed into Duse Bay overnight, but on departure, we stood in the bridge while the captain navigated through a beautiful but dangerous huge minefield of growlers and bergy bits. Calmly but confidently, he dictated rapid-fire helm adjustments as the ship moved forward at a brisk 15kn, slowing down only occasionally, swaying back and forth as it avoided the obstacles (the roll increased because the stabilisers are withdrawn to avoid ice damage). It's awe inspiring to witness such a professional at work, only an hour after he too had completed the polar plunge.

The Orion has to make its way through this sea of ice, skirting all the bigger bergs.

As we sailed east out of the Weddell Sea towards Paulet Island and starbord of another (both completely bare of snow), we closely passed one of the biggest tabular icebergs (if they have names, we don't know what they are). Way out on the starbord horizon and barely visible it was so far away, there was, we were told, the biggest of all, some 50km long.

That distant tabular iceberg is 20x4km. Paulet Island in the distance.

The captain gave us a close look at the end of the 20km iceberg.

Adelie penguins watch the Orion as it steams by.

Some features are remarkable for their total lack of snow.

The Weddell Sea is an appropriate place to see these two Weddell seals.

For hours on end we traversed this field of icy floaters in the Weddell Sea. Many of the bergy bits we go by have a pair of Adelie penguins, or a dozen, taking a break from their food hunting. If the Orion comes too close, they wisely abandon their berg and dive into the sea. The water is so clear, the undersea portion of the berg is clearly visible from our ship. We see Weddell seals basking, and many petrels soaring.

Many Cape Petrels soared around the Orion.

Crystal clear blue water exposes a growler's underside.

Another totally unsnowed promontory.

Sunset and only one tabular iceberg is visible in the distance.

The ice density at the northern part of the Weddell Sea seems to vary greatly. Overnight, there was drama on the bridge as heavy fog descended in an intense ice field. The Orion could not proceed safely and had to reverse out to take a different route in very poor visibility. By dawn, now in the Scotia Sea, all that was visible was a grey sky, good visibility and myriads of tiny growlers.

The overnight drama led to a fantastic presentation by Captain Martin Kesser in the passengers' lounge on the hazards techniques of ice navigation, especially with the complications of wind and current, both of which can be very strong. He told us that this was the presentation he gives to new officers and crew. New technology and the availability of polar-orbit satellite ice maps makes it a whole lot easier than it used to be, but still a great challenge. The satellites don't pick up smaller bergs or any ice cover less than 2/10, so they can still give false impressions of clear water. He explained that the Orion has an A1 ice-class which is just under the best commercial rating short of ice-breaking vessels. To get the A1 rating, the Orion has hull reinforcement, stern reinforcement (for sharp turns) and special treatment to rudder and propellor.

Erin McFadden (undersea specialist) and Robert Alexander (dive master / naturalist) gave a fascinating demonstration today of the equipment they wear to go underwater in the Antarctic. The total weight of the gear is about 45kg, and with all that on, they are virtually helpless without a buddy system going and help from the able-bodied seaman (AB) who invariably accompanies them. As Erin described the process, Robert put on the equipment in the 4th level lounge. Two more very impressive professionals in action. And, because there is no stage in the lounge, Ian Strachan filmed the procedings on his iPhone and transmitted it real-time to the multiple screened AV system in the lounge - an impressive use of technology!

Erin McFadden and Robert Alexander demonstrating their frigid water dive gear.

Ian Strachan transmitting the video of the dive gear presentation to all the Orion's screens.

Bad weather is forecast for the Antarctic, so the Orion is leaving the Weddell Sea a day early, bound for the South Orkney Islands.