Burrows estimated that fifty to seventy percent of the prison ship detainees died. When given the option of boarding a ship like the Jersey or joining the British, several captives chose the latter. Prisoners on board the Good Hope allegedly set fire to it, rejoicing as it burned into the water. An equivalent estimate was made for the other ships carrying captives: between one-third and one-half.
The real figure may be higher than Burrows's estimate because not all deaths were reported.
Also, some survivors claimed that many more prisoners had died than had been recorded. A government report in 1831 concluded that about four out of five prisoners on board the ships had died. This would mean that about one in five had survived.
In addition, there are reports of people being taken to Britain who could not have escaped from its ports because they were under arrest with no possibility of release. For example, in 1756 George Louis de Schweinitz wrote that around 300 Americans were being held in London in "prison ships".
This shows that at least one in seven of those captured by the British during the Revolutionary War died while in their custody.
The prison ships, often known as "floating prisons" or "ghost ships," were little more than maritime concentration camps, responsible for thousands of deaths. HMS Falmouth, Scorpion, and Hunter were among the 16-odd prison ships. The most infamous, though, was Jersey. She was a 468-ton ferry built in 1776 that was converted into a floating jail at the behest of New Jersey politicians who did not want prisoners taken downriver where facilities were scarce.
Jersey was fitted out with 20 cells and a small armory, and she first sailed up the Raritan River on January 11, 1777. It is estimated that she held between 150 and 200 prisoners, mostly Americans captured during raids or while trying to escape. Prisoners were given three meals a day, but there were no doctors on board so anyone suffering from illness or injury had no choice but to wait until they died.
It has been suggested that the strong odor emanating from Jersey's filth-ridden decks may have prompted some prisoners to kill themselves by jumping off her side. This seems likely since there are reports of bodies being found on shore after such an occurrence.
In addition to those killed while still aboard her, another estimate puts the total number of people who died while imprisoned on Jersey between 1777 and 1825 at 1,560. This includes soldiers executed for crimes they didn't commit and civilians including children sent to jail for minor offenses.
A year later, in 1838, there was a severe outbreak of scurvy on board the ship Lord Lyndoch, affecting more than 150 prisoners. When the ship landed in Sydney, eight prisoners perished at sea, and 113 were transported to the hospital. Twenty of these inmates died in the hospital.
The disease is caused by a lack of vitamin C in the body. It can be treated with a fresh fruit infusion or supplement. The mortality rate from scurvy was very high in early Australia - about one in two people who developed it didn't survive. Today, scurvy is rare in developed countries because they usually have access to plenty of vegetables and fruits that contain vitamin C.
There were also several fatal cases of dysentery on board the ships, which was common during transportations between Australia and New South Wales. Dysentery is caused by a bacteria spread through contaminated water or food. It can cause blood and mucus to appear in your stool and can even lead to death if left untreated.
Another danger for convicts was heat stroke. During transportation, the temperature in cells could reach 45 degrees Celsius. Heatstroke occurs when the body cannot cool itself down enough and its core temperature rises. Without immediate medical attention, it can lead to brain damage or even death.
Convicts also had accidents while working on board ships.
On coffin ships, 20%–50% of passengers, or up to five out of every 10 persons, perished before reaching shore. Historians believe that up to 100,000 people died on coffin ships seeking to escape the Great Famine!
Coffin ships were large ships used by the British trade route for transporting slaves from Africa to the Caribbean and South America. The slave trade was banned by an 1807 act of Parliament but not completely stopped until 1833. After that time, pirates took over this job of shipping out slaves.
People would pay good money to be transported to countries where they could work and earn a living. But many died during the voyage, either because they weren't given enough food or water, or due to disease or violence once they reached their destination.
The number of deaths on these ships was higher than that due to combat or disease. This is because many people survived the ordeal of the voyage but then had no chance of survival once they reached land. For example, almost all of the people who arrived in Texas as slaves didn't live long enough to reproduce or move away from the plantation system.
It's estimated that between 20% and 50% of those on coffin ships died before reaching land. This means that between 25,000 and 50,000 people lost their lives in this way.