NavList:

Paul Dolkas you wrote:
"Along those same lines, here is an interesting article on a "Coconut Sextant",  used by the ancient Hawaiians & Polynesians"

This is not history. It's a fanciful speculation. First of all, any time you hear someone talk about things used by "ancient" Polynesians, be suspicious. We know next to nothing about the practice of ancient Polynesian navigation because they left no written records, and their tools were all perishable, almost without exception. We do have some details on Polynesian navigation at the time of European contact, and of course we know that earlier generations sailed and populated the enormous "Polynesian Triangle" in the Pacific over the course of some centuries. But that's about it. Anyone who tells you, "here's the tool they used to measure latitude" is making it up on the go.

The detailed desciption you found:
"made from a coconut shell cut across at a slanting angle with a hole at the low end, and a notch at the top end, and a number of holes encircling it. These sat above a wavy line representing the ocean and underneath an arch of ten stars evenly spaced. The coconut shell was filled with seawater to the ring of the holes. Coconut oil was used to preserve the surface tension of the seawater and, (within reason), to prevent leakage from the ring of holes."

...is bullshit. This sort of detailed explanation without documentation is just the sort of thing that fuels bad history. The invented details create the illusion of scholarship.

The "coconut sextant" is a modern concept designed to satisfy the instrumentality-focused interests of western navigation enthusiasts. Sadly, there are today Polynesians who have also fallen for this quackery. 

Frank Reed