The Caribbean side of Panama attracts a type of tourist few other places see: seafaring backpackers. That there pic of the West Holandes anchorage in Panama's San Blas islands, is a view of several vessels that serve this subset of the adventure travel community. In fact, The Fox was the only boat in this view, that was not a backpacker boat.
From what we saw during our time in the San Blas, the typical seagoing backpacker is an adventurous 20-to-30-something, single, white, and middle class. They're seeing Latin America on the cheap and want to experience the Spanish Colonial city of Cartagena and see a bit of Eastern Panama, one of the world's last non-industrialized areas. In Eastern Panama, the through-roads on shore - hence, the buses and other land-based public transportation - peter out a few miles SE of Portobelo, Panama. The only reasonable way to get from Panama to Colombia in this roadless area is by plane ($$$) or charter boat ($$). If these young adventurers can make it as far as either Panama City or Cartagena, the backpacker boats are waiting to take them the rest of the way.
We've seen that the boats themselves - with very few exceptions - are in various stages of disrepair. We saw one large vessel whose transom was completely blackened by smoke from its malfunctioning diesel engine; it listed heavily to stern, suggesting it had no working pump to empty the water that was obviously filling one of its bilges. It had clearly been a long time since the owner had paid for any repairs, yet the boat's website (prominently advertised in a banner along the deck) showed photos of the same boat in much better condition. Must have been old photos.
Invariably the backpacker boats we saw en route to Cartagena were overloaded with passengers - such as the 36-foot sailboat we saw carrying 8 backpackers - so when night falls the skippers take their passengers ashore by dinghy to sleep on the beach since the boat cannot accomodate so many people. Safety gear (flares, life jackets, medical supplies) appear to be sparse to nonexistent from what we can see on the decks.
Panama does not regulate the backpacker-boat trade. It's generally a cash-only business that anyone of any nationality can start up. There's no government oversight - Panama remains unaware of exactly how many boats are in the backpacker/charter trade. But there's always a fresh crop of young adventurers coming in to Panama who are willing to pay $450 for a boat trip to Colombia.
There's nothing wrong with touring the world by backpack and boat - but it can be treacherous doing this in Panama. At best, it's virtually impossible for a person (especially someone unfamiliar with boats) to know ahead of time exactly what how well equipped (i.e., how safe) a boat is, or how competent a skipper actually is - in this territory, the promises a charter boat's owner/operator makes are not necessarily kept. You might find once you're aboard your boat that your skipper is a drug trafficker, or serial killer. At worst, you might find yourself in the water clinging on to a fender because the skipper who took your $450 ran his boat up on a reef in the middle of a storm and did not have enough life jackets to go around. It's happened - snorkel the narrow entrance channel into Chichime in the San Blas, and you'll see the wreck of the s/v Twyla about 10 feet beneath you.
In the future Panama may slowly begin to observe - and perhaps even regulate - the backpacker boat trade. They should; from what we saw many of these boats deliver much less than they're selling. And I'll say it again: some of these boats are in such a state of disrepair they're hazardous. There are no US Coast Guard safety regulations to protect you, and the police are very far away.
There are legitimate operators running the backpacking trade to and from Colombia. How can you tell who they are? I can only suggest that a prospective seafaring backpacker study well before giving someone in Panama $450 for a boat trip to Colombia. Captain Jack, who owns Captain Jack's hostel in Portobelo, Panama, is an excellent source for current, reliable information. Plus his hostel/cafe is a very cool place to visit anyway. Word of mouth is a powerful thing, too - pay attention to other backpackers' experiences and don't just stop with a Google of "backpacker charter boats; portobelo".
Be careful out there, stay informed, and you'll have a wonderful adventure!