Those are Peta’s written words to her mother – words that, in retrospect, hold such poignant irony. By now, she and Chris had been in Boston’s company for approaching two weeks. She wrote to her mother:

‘In Belize City, we had to pay $86 BH for visas to enter into Honduras. It seems that there’s nothing but hassle and money to go anywhere by boat. Chris has been doing a lot of sailing and even I have been taking the tiller a couple of times – very tiring, depending on the strength of the wind.’

Peta mentions that their schedule was seriously disrupted because Boston wanted to get ballast [heavy material, such as sand, gravel or iron, added to a boat to improve stability and control], offering perhaps the lengthy voyage in less protected waters down to Costa Rica to sell the boat as the reason.

‘We had to spend nearly a week at Stann Creek (Dangriga) trying to get extra ballast. Finally, we were given about 700 lbs by a white Belizean, who is the general manager of the Belizean Citrus Co at Pomona, about 12 miles from Stann Creek. He gave us a tour of the factory – very impressive. They make concentrated orange juice and tinned grapefruit, most of which goes to the UK under the name of Trout Hall. Have you seen any? He gave us a few tins – very good for breakfast, though you know I don’t like it much. We had to get a whole load of papers stamped for customs clearance etc and paid $10 BH, which went straight into the officer’s pocket, of course.’

Sailing on to the quiet Belizean fishing port of Placencia, Peta wrote:

‘When we arrived, we were longing for ice-cold beer as usual (sailing makes you so thirsty) and we didn’t have much water on board but there was no beer or soft drinks in town! Placencia is very pretty. It can only be reached by four-wheel drive and is built on sand with a narrow cement pathway linking the houses etc.’

Its narrow meandering sidewalk served as its main street and, like so many of the islands in this part of the world, it had a white sand, palm-fringed beach.

The beauty of their surroundings was not, however, uppermost in Boston’s mind. Finding some poisonous seeds in the sand under some trees on the beach, Vince and Russell showed them to their father, who took the red and black seeds from them. Boston looked the seeds up in a book of local flora and fauna that was on the boat and said: ‘I should feed these to Chris and Peta.’

Russell recalled many years later: ‘It struck me as odd and it lodged in my head, both at the time and since, but I thought it was just Dad being drunk and spewing idle threats. Nonetheless, Vince and I hid the seeds from him.’

On 28 June 1978, Peta wrote to her mother: ‘We have just set off from Placencia and it’s about 7am. The sun is warm, the sky a little cloudy and the sea is emerald green and somewhat choppy so my writing may go haywire.’

Sailing south the next day, the Justin B reached the small island of Hunting Caye – one of the Sapodilla Cayes on the very southernmost tip of Belize’s beautiful barrier reef. Halfmoon Beach, a sandy coral beach named after its crescent shape, is on the eastern shore and is an important nesting site for the Hawksbill sea turtle. The coast is paradisiacal, with reefs, white-sand beaches and crystal-clear waters teaming with life and miles of mangroves.

Impressed by what she saw, Peta wrote in a postscript on the 29 June: ‘We had a perfect sail and reached Hunting Caye at about 11am. (Chris wants me to say this was due to his superb navigation with only a $5 compass.) This caye is very pretty. The only person who lives on it (it’s about 500 yards by 100 yards) is the lighthouse keeper. We were surprised to see the pelicans (everywhere here, but not pretty as they’re brown) roosting in the coconut palms. With the wonders of modern civilisation, this place would be an idyllic Caribbean island. We’ve docked only about 50 yards offshore and the water is perfectly clear. There’s a reef some way off and another four cayes visible. We caught a lobster and sardines last night.

‘I was very pleased yesterday when I managed to make some “fry-jack” – a flatbread fried in the pan. I’d only watched Tom, the sailor I told you about and who has now left the boat, make it once and he was a baker.

‘Talking to the lighthouse keeper, this is the worst time for sailing and our next sail to Puerto Cortes in Honduras would be very hard, so it seems we may easily decide to go to Livingston in Guatemala, which is a simple sail with the wind behind us.

‘If we do, I shall leave the Justin B and get a ferry to Puerto Cortes and a plane from Honduras to New Orleans.’ [Whilst Chris had a short-term medical job in Trinidad, she was going to visit a close mutual friend – a Dr Tom Lane who lived in Louisiana, USA.]

For the first time, one senses tension and friction beginning to creep into Peta’s writing. She describes the boat’s cramped conditions and how tempers were starting to fray:

‘I am getting a bit weary of the practical difficulties of living on this tiny boat with four other people. At least I managed to get a shower at Placencia by throwing buckets of well-water over me. I think I’m getting too old for primitive living. Like all boats, this one has cockroaches. We sleep in the galley, a space about 4 foot by 5 foot by 2½ foot. It’s horrible when we turn on the kerosene lamp and they come out. We spray a repellent every day but they come out to die. I don’t mind cockroaches that much, there were loads in Morocco and Australia, but I like a little space between me and them.’

Significantly, she writes: ‘Another reason I wouldn’t mind ending my sailing career now – I’m down as a sailor on the papers – is the two sons of Duane. They are 12 and 13 years old but behave more like 8 and 9. I find I have no patience at all with them. Of course, they squabble most of the time. I now see how irritating we must have been as children in that respect.’

With chilling prescience, she adds: ‘But, on a boat there’s nowhere to go. What makes it worse is that Duane curses and puts them down continually, often when things are not going quite right, like when we didn’t get one of the anchors up because the motor wasn’t working to give us leverage. We subsequently went back for it and managed to retrieve it – about $100 worth.

‘Time seems to go so quickly here – it’s nearly July already. It must be getting quite warm now in England. Did I hear there’s going to be a General Election? I haven’t seen a newspaper for weeks and the BBC World Service doesn’t give much about the UK. I often wonder what everyone is doing and I feel very cut off, but letters are too difficult as I never know where I am going to be next.’

‘I’m already a month late at Tom’s in New Orleans but I’m looking forward to getting there as the music’s supposed to be excellent in the pubs. Of course, it’ll be about 30 degrees and very humid, but I guess I’ve gotten used to it a bit and it makes a lot of difference having a shower etc.’

She signs off her last-ever letter: ‘Enough of the future. I don’t think there’s any more news – nothing much happens on a boat. Lots of love Peta.’

But an awful lot was about to happen on that boat: we were to never hear from them again.