Mindbender

How is a sailboat’s hull speed (sometimes called displacement speed) calculated?

Send your answer to cruisingcompass@bwsailing.com. A winner, who will receive a Blue Water Sailing hat, will be selected at random from the correct answers.

Thanks to last week’s Mindbender winner, Tim Luker, for his answer to “Using the tide chart here and the “Rule of Twelfths,” what will the height of the tide be at 8:30 AM?”: 08:30am is 2/3rds along from low tide at 04:05am and high tide at 10.38am. The RoT states tides increases/decreases in steps of 1-2-3-3-2-1 twelfths of the tidal range of 8.7ft (1/12 = 0.725 ft). Therefore, at 08:30 tide height is 1.0 ft + (1+2+3+3) x 0.725 = 7.525 feet.

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