"A Mermaid" by John William Waterhouse.
Mermaids hover between the zones of make believe and reality, often coming dangerously close to the latter. Historic sailors such as Christopher Columbus have asserted that they exist, though are not half as pretty as they are purported to be. Years spent at sea on a diet of rum and no female company can do things to your imagination, and make frolicking dolphins assume female forms.
We may however, have to give Columbus and his ilk the benefit of the doubt, because mermaids have been a part of folklore since the ancient times. The classic depiction was that of a mermaid seated on a rock, combing her long tresses while gazing absentmindedly into an ornate handheld mirror. They were supposed to be fantastically beautiful once you got used to the fishy smell, and had great powers of enticements. A wicked temper to go with this beauty often spelt trouble for lovers or whoever happened to catch their fancy.
The Fisherman and the Syren, by Frederic Leighton, c. 1856–1858
In Greek mythology, mermaids or their equivalents were often the result of gods taking their amorous escapades to the realm of the sea. The Sirens would have to be the most famous of these creatures. Homer’s Odyssey has a riveting account of the hero Ulysses’ encounter with the Sirens. Warned by Circe, he plugged the ears of his crew with wax, but not before ordering them to tie him up to the mast head. This accomplished, he was witness to the powerful tempting voices of the Sirens that lured him closer. The whole point of the exercise was to get them to crash the vessel on the jagged rocks beneath the foam and be dashed to pieces. Though what they sought to gain from this would be anyone’s guess, it does point to the hazards of having a lot of free time on your hands.
Marriages between mortals and mermaids are not unknown in mythology, and the most recent example would be that of Hans Anderson’s Little Mermaid. But not all these matrimonial engagements have similar happy endings and most are often do or die efforts, on the part of the mortal. Mermaids pose great danger to their mortal partners due to their streaks of cruelty and irresponsibility. Incompatibilities ranging from mermaids’ inability to walk on land and the mortals’ inability to breather under water often pose great problems. They are known to drag the mortal chap deep into the waters often forgetting this fact, though this might be just their way of teaching recalcitrant partners a lesson.