We took three months to plan the trip online. Some of us were strangers and the only binding factor was we each owned folding kayaks that could be collapsed into backpacks for easy transportation.

We met at Polonia Airport in Medan before heading for the lake. I was the first to arrive with a 19kg backpack containing food and a kayak.

A customs officer asked: ‘What is it?’

I answered: ‘Sampan.’

When everyone had arrived, we embarked on a bumpy four-hour 180km ride to Tigaraja ferry terminal in Prapat town, right on the edge of Lake Toba.

Boats at this terminal head mostly for Samosir, an island in the middle of the lake. There are no pre-designated ferry stops. Passengers simply give the name of their accommodation and alight at the piers nearest to their hotels.

At dusk, we got off at a tiny pier built for Romlan, a traditional Batak house hostel run by a German woman in Tuk Tuk town on Samosir Island.

Night was falling and with the help of torches, we struggled to assemble our kayaks. But something was wrong. My kayak was missing an aluminium rod, integral for stretching and supporting the skin to keep it afloat. I had left it behind in Singapore. My heart sank.

The new blue kayak was to have its debut row on Lake Toba. I had even christened it Toby.

My new friends scoured the area for a substitute rod and found a piece of bamboo. They sculpted ’screws’ for the rod out of tree bark and used plastic cable ties to secure the rod and Toby was ready to go.

The next day, we rowed 55km south to Muara town, passing several waterfalls teeming with jumping fish.

Once in a while, cranes flew by and eagles descended to the water to fish, like a scene out of National Geographic.

There were only a few hours of morning light before the crater lake became shrouded in mist. In the afternoon, the mist condensed into clouds, lingering low on the hills.

The water temperature had fallen over the last few years to about 24 deg C due to global weather changes. So going to the restroom was a cold ordeal because it involved jumping into the water.

When it stormed in the evening, the lake churned up rough waves that could overturn small kayaks. The storm also sent winds so chilly that even windbreakers could not keep us warm and heavy raindrops beat down painfully on our tired bodies.

It became essential to have lightsticks strapped to our life jackets so we could spot one another easily.

We munched on muesli and nuts to keep energy levels up and drank from bottles of water we had stored in the sterns and bows of our kayaks.

It was a relief to finally reach the town of Muara where we spent the night in Wisma Muara Nauli, a hotel that was still in its final stages of construction.

The next morning, as we left the hotel, locals in motorboats stared at us with puzzled looks.

Rowing a boat apparently is for the poor who do it out of necessity. And nobody kayaks in Lake Toba.

Halim, who has lived in Indonesia for more than 10 years, explained: ‘The idea of paddling a boat is absolutely crazy to the locals, it is a lapse into backwardness. Once they can afford motorised boats, it is absurd to use such a primitive form to move a boat forward.’

That night, we got lost when the batteries of the GPS system ran out after 16 hours of paddling. Even with a full moon overhead, differentiating Samosir Island - our key landmark - from the various hills and crevasses was impossible.

Finally, at midnight, we found Sampean. The family hosting us ran out of their homes, shining lights onto the dark water to guide the paddlers. They served a meal of mee gomak - noodles with a very hot sauce made of peanuts and grounded chilli padi.

On day three, paddling north to Silalahi, a remote sleepy village, revealed more of the lake’s beauty, as the hills surrounding it were filled with flowers.

You spot more Christian tombs than humans, scattered all over the hills. The Bataks were converted by American missionaries in the 19th century. Today, on Samosir Island, which is also called the Island of the Dead because of the tombs, locals practise a mix of animistic beliefs and Christianity.

The villagers at Silalahi made an impression on us on the last night. They gathered at the only restaurant in their town situated along the lake, anticipating our arrival. They had prepared a song and dance to welcome us, and also called a TV crew from Medan to film our arrival.

But we were four hours late and we arrived in a storm.

Still, the villagers ran out to welcome us, making their way down slippery rocks to carry the kayaks ashore.

David, the restaurant manager from Morina guesthouse, had his employees move all the tables and chairs outside into the rain, so our kayaks could be kept safely inside for the night. They also whipped up a stunning meal of Toba french fries and local dishes.

The next morning, the village chief danced and sang before we left. Young and old, they stood in line to shout, ‘Horas! Horas! Horas!’ (a Batak greeting that means God bless).

Finally, on the fourth day, we paddled into Tongging village to disassemble the kayaks and a van took us to the airport.