Audio gauge meter testing of a steel hulled houseboat. 4.4 mm is 0.1732283 inches. Many steel boat builders are using 1/8th inch (0.125) material.
Audio gauge meter testing of a steel hulled houseboat. 3.9 mm is 0.1535433 inches. Many steel boat builders are using 1/8th inch (0.125) material.
This photo shows an Outdrive that did not have protection from stray electrical current. The white spots are either very nearly holes in the housing or "are" holes in the housing. Very expensive, a $ 30 sacrificial anode would have prevented this.