Non-boaters might be startled to hear someone say, "You better go get your bottom scraped" Boaters, hear that often and they know very well which bottom that refers to.
In all the years, we sailed on Sacandaga Lake, and Lake Champlain, and on the Baltic Sea, we never had to worry about bottom scraping. But when we moved on Tarwathie, and started cruising in salt water, especially in the sub-tropics, it became a reality very fast.
Below is a picture the first time we hauled Tarwathie out of the water in 2005, after owning her only three months. With so many barnacles on the prop, I was only able to make 1 knot speed against the tide at full throttle. That was a very quick education.
Still not impressed? Below is a picture of another boat after one year in Marathon without cleaning the bottom.
Historical stories make it sound that the reason that ancient ships were routinely careened was shipworms. Shipworms were certainly a problem for wooden hulls, but they are far from the only problem. Then, as now, an unclean boat bottom will wreck your ability to move through the water swiftly.
Nor was careening the only solution, Copper cladding was the ancient equivalent to today's copper-based bottom paint.
|Model of copper clad ship.|