As the launch moves out of the still water at the quayside, I see a plain clothes DAS man, machine gun at the ready, give a powerful kick to the wooden door of one of the waterfront houses. The door flies open, but already the DAS man is taking cover alongside the door, his back pressed hard to the wood next to the door frame, his gun ready to argue violently. I do not see any more of this strong reality, but I know that the image is etched on my mind... but thankfully, right now, it's goodbye to Turbo!

We go at a fairly leisurely rate for some miles, avoiding the rafts of vegetation that float everywhere, and then the pilot opens up, and the whole launch adopts a high-speed angle as we blast off. It takes hours to get to Acandí, past lonely cabins far off on the distant palm-covered beaches to the port side. We have a brief stop in Capurgana where we get a pretty visa from the Panamanian Consular Office to decorate our passports, although he insists we don't need it to get into Panama. We, however, prefer to have the stamp, which may help us as we don't quite have the correct amount of money that we have heard we need to enter Panama. We set off again, and some time later the engines finally ease off and we come to Acandí.

Much of the township is out of doors waiting to see what the launch has brought them. They scowl at me, but stare with disbelief at Leo as they crowd round him. We are told we must show ourselves to the police since they want to know what is going on at all times. There are many people now surrounding Leo and the children are pulling his hair. Leo is pleased and roars with delight. The people cannot believe that Leo's hair is real, but he loudly insists that the people feel his hair and know that it is real. He is loving it, a real star, his brilliant white teeth flashing in a huge smile. When our babbling entourage reaches the police hut, the police are grumpy and dismissive. We go into a bar to have a drink of orangeade and a man there turns to me and says that they do not care about me. It is only because of Leo that they leave me alone and that I should be glad that Leo is with me. The gringo is not liked around these parts.

I am somewhat relieved that a longboat is going to Zapzurro very soon and that we will be on it. There are only four of us on the journey, so there is no problem with space. We happily jump aboard and finally, comfortably, we reach Zapzurro, the last coastal village of South America. We find ourselves in a perfectly idyllic setting - the whole atmosphere of Zapzurro is friendly and laid back. There is no basuco here, and villagers are at ease with everyone. We find a hotel and I note with great delight that there is a mosquito net over the bed. This is a nice place, an oasis indeed.

Our belongings now safely stashed in the room, we go for a walk and reach the coastline within sight of the village. I stare longingly at the lovely clean clear and deep water and see tropical marine fish darting around the coral. There are clownfish aplenty. Water like this begs you to swim and enjoy, and I am quite unable to resist. Leo likewise seizes the moment, and we peel off to our underwear and dive in, swimming with joy. It's so lovely and warm, shoals of small fish, great visibility underwater, so clean is the sand, so so good. The only thing stopping me from swimming naked for the full experience is the haunting story I have heard of some outrageous fish that likes nothing better than to bite one's penis off. Another sobering influence, of course, is the filthy rotten candirú fish that enjoys wriggling its really slippery body into the urethra.

Further along, at a coral outcrop, we both see a flash of yellow and black and a snake-like form disappearing into the coral. Leo is excited and says we should kill it. I get out my geological hammer and begin to probe the area. Leo waits with the knife. My hammer is light enough to move quickly and heavy enough to deal a serious blow to a snake. I glance at Leo, and he is wide awake holding the blade at the ready. The snake does not respond to our advances, so we leave.

I experiment with my water survival filter bag, and pour dark brown muddy swamp water into it. This is its first real test, as the water of Bogotá had only amoebas in it - easily filterable. The filter rate of this swamp water is unsurprisingly slow, but the water, after treatment with water purifying tablets, is remarkably potable - much more so than any fluoridated mains tap water of England. We move on and sit in the refreshing shade under wild mango trees, and eat the sweet juicy fruit. We find almonds also abound, and we break open some kernels for the delicious fresh nuts inside, but it's hard work.

Later, that night, we fish in the small harbour using the remaining crabline from my fishing outfit. Leo catches a fish and we haul it up onto the jetty. It is some sort of flatfish having a long tail with vicious spines that flicks and lashes out at us constantly until Leo cuts it off. We cook and eat its jelly-like flesh. I find I do not wish to repeat this culinary experience.

The next day, we find a boatman willing to take us to the first village in Panama, Puerto Obaldia, and we agree a price. The boatman looks firmly at Leo's dreadlocks and says there must be no marijuana. Leo is greatly put out by this, but the boatman is adamant and wants there to be no trace whatsoever since he does not wish to be accused of being a drug smuggler. Leo agrees very reluctantly and throws his weed overboard in front of the boatman who smiles broadly and nods his head. We begin the fifth and most significant leg of the journey.