The sun is shining, the sea is sparkling and a whole pod of humpback whales have been putting on the most spectacular display, leaping out of the water so close you can see the white and dark patterns on their bellies.
It is a thrill to be near these big mammals, and everyone on the pool deck who gathered to watch some of the scientific equipment lowered into the sea, forgot about that for the moment and charged over to the rail to watch the humpbacks.
As the whales departed, the group turned their attention back to something called the Ski Monkey. Not anything to do with an acrobatic primate, but the name given to a super sophisticated underwater camera, housed in a big steel contraption that is winched up and lowered over the side of the ship into the ocean.
It can work up to a depth of 600 m and takes both videos and photographs, which can be seen on computers on board in real time.
The scientific staff, the crew and the bridge are all in radio contact at times like this, so the scientists can ask the ship to slow down to almost a crawl while the equipment is being deployed.
Once the ship's crew had lowered the Ski Monkey into the water, everyone went back into the lab and watched the scientists take over the control of the winch via a computer.
One person kept a watch on the depth as it descended, calling out to her colleague on another computer where she controlled the speed at which it was lowered.
The computer screen was blue as it went down through the water, and then suddenly the brown sandy bottom appeared at about 80m. This was the time to call up to the bridge to get the ship moving again very slowly so the camera could move along filming a few metres above the sea bed.
Oceanographer Laurenne Snyders picked up the radio: "Bridge ops, please start towing at 0.3 knots."
The ship starts moving almost imperceptibly.
The room was quiet as everyone watched the sandy bottom glide beneath them.
"We look for anything that catches our eyes, so we can get an idea of the substrate or sea bottom," Snyders said.
After miles and miles of just sand, Snyders was just about to call up to the bridge to raise the camera, when a collective: "Aaah!" went up from everyone watching.
The dull sandy seabed has suddenly changed into a colourful array of sponges and corals - blues and yellows and reds.
Robyn Payne, who is doing her doctorate on sponges, was ecstatic.
"Ah, they are just so amazing!"
She found four new species on the Agulhas's trip up the east coast of Africa earlier this month.
Payne said sponges were important habitat for certain fish species, while there has been a lot of interest in the chemical composition of sponges from pharmaceutical companies for possible medicinal qualities.
"Sponges are really fascinating," she said.
It was decided to nickname her Sponge Rob.
The other piece of equipment deployed was something called the CTD, which weighs about 1.2 t and costs around R5-million.
It is a cluster of about 12 metal cylinders designed to collect sea water and to transmit a variety of information back to the laboratory, such as ocean salinity, temperature and depth.
Crew open a huge door in the side of the ship to deploy this machine, which is lifted by winch and lowered into the sea.
The cable that attaches the CTD to the winch both supports it and houses a link from the machine to computers in the lab.
In the lab, physical oceanographer Hassan Ismail radios to the crew: "Okay boson, take it down to 200 m."
He watches through a window as it goes overboard.
"Okay, we'll take over winch 6," he says as he wiggles a tiny joystick on the computer.
EXPLORING THE INDIAN OCEAN
On another computer, there are a lot of what appear to be just coloured squiggles, but to the scientists they are relaying a whole bunch of information.
When the machine reaches a certain depth, the cylinders are filled with seawater and it is lifted back on board, waters cascading off it, and is lowered onto the deck.
Scientific technician Kanyisile Vena gets first dabs at taking samples of the seawater. She is measuring dissolved oxygen in the water.
Then comes Baxolele Mdokwana who takes samples to measure dissolved inorganic carbon.
After that, other scientists will take samples later to look at various biological and physical properties in the seawater.
The SA Agulhas 2 is on its way back to Cape Town after a research cruise up east Africa and to the Comores, part of the UN's second International Indian Ocean Expedition. The first was in the 1960s.
Ashley Johnson, the Department of Environmental Affairs' director of research and leader of research cruise, said the Indian Ocean was the least studied of the world's oceans, as it was surrounded by countries with the least resources.
Former president Nelson Mandela had pushed for the founding of the Indian Ocean Rim Association, as he recognised that Indian Ocean countries would need to work together to remedy that.
By taking scientists and students from Tanzania and the Comores on the cruise over the past few weeks, South Africa was working towards that goal.