A group of divers rowed up alongside the MV Aboshar in their wooden boat and were soon chatting to Masud Khan, the presenter of the BBC Bengali Service's programmes along our journey through Bangladesh.
But their own story was compelling. One of the divers explained how he was taught by his older brother how to free dive - without oxygen - in the search for goods lost in the many sunken vessels along this stretch of river.
One haul of grain - which they brought up, dried out in the sun, and sold on - had landed them 25,000 taka (£180), a substantial sum. But not everyone is doing so well out of the river, as we found when we made our first proper stop, at Chandpur.
Being built around the confluence of the Meghna and Padma rivers has made Chandpur historically one of Bangladesh's most important trading centres - but also made it extremely vulnerable to erosion.
And it is clear on entering the town how it is being affected. Particularly on the western bank of the Meghna, things have a temporary, broken look, and in places the bare soil simply drops into the water.
The police station is being taken down to save materials
Quite a few people have turned up to meet us, and after we leave the boat we are escorted through the main fish processing plant - and this, at least, is still bustling.
Chandpur is the principle town for the landing, preserving and distributing of hilsa, Bangladesh's national fish. The slender, silver fish are everywhere: frozen in buckets of ice, set out in circles in wicker baskets, and even packed together in a single, two metre cube - on top of which a man sat, scowling at passers-by.
Why he found it necessary to actually seat himself on it was impossible to say - it was not as if such a thing is exactly easy to steal. Fortunately for him, as the fish were salted, it did not smell too bad.
But it did at least leave the impression that not everyone is struggling in Chandpur, and in some respects it was still thriving. This would not be the case elsewhere.
30 October - FRESHLY EXPOSED
The next day we travelled to the town of Haimchar - or more accurately, what is left of it.
Before we even landed, the dramatic effect of river erosion was clear from the boat. The entire riverbank is around a metre or two of freshly-exposed soil, and several palm trees floating in the water. These, we were told, had been growing on the river bank as recently as three days ago, before simply falling in as the ground they were planted in was washed away.
Already, 5,000 residents have been forced to leave their homes, which have crumbled into the river.
And when we arrived in the town, we saw those that remain working in tremendous heat to take down the town's police station, in order to salvage the bricks.
For 200 years, Haimchar had been home to a thriving market - but, as in Chandpur, this had been lost to the water.
We spoke to one woman of 60, who is now homeless after the river claimed her house. She now lives by the side of the road.
What is noticeable on a look round the town is that it does not extend back very far. It is not difficult to draw the conclusion that if the current rate of erosion keeps up, it will simply have disappeared in very few years.
31 October - INSECT BOMBARDMENT
There were yet more indications of the impact the ever-expanding rivers are having when we travelled further south to Hijla the day after.
There, an entire school has had to move inland after it became clear, seven years ago, the building was about to fall into the river.
Around half the children will go into fishing or farming
What exists there now is a very basic temporary structure in which four teachers are in charge of 271 children. But the headmaster is proud of the school; it has some of the best results in the district, with pass rates approaching 100%.
As well as the standard subjects in the curriculum, the children here receive lessons in what to do in flooding, such as how to preserve food and clothing, and to make sure they boil water before drinking it.
In this part of the country, the river advances inward by around 200 metres every year.
One farmer, who has won awards from the government for his skill at cattle-rearing, told me that with the current rate of erosion the water will be at his farm within a year. The impact of erosion and expanding rivers on farming is something we will see more of at our next stop, in Bhola, an island of silt that is possibly Bangladesh's most vulnerable place.
That night we returned to the boat and put up large nets over the windows to help stop the astonishing bombardment of insects which have made working nearly impossible.
Thousands of them - moths, beetles and dragonflies - have launched themselves at the boat from around sunset, attracted by our lights and laptop screens. They even crawled between the keys as we typed.
Fortunately the nets seem to have done the trick - so we are able to keep going and bringing you the story of this extraordinary journey.