Working at a speed of two knots, HMS Protector broke the four-metre thick ice, which had trapped the cruise ship's bow, in two hours.

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The top speed is just two knots.

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The two boats are now towing the Triumph at about 6 knots (6.9 mph).

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Each night, they spent two hours preparing a dozen or so rods, checking knots, sharpening and baiting hooks for the next day.

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For example, you're two miles out from a helicopter landing zone, flying 230 knots as an airplane.

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Personally, I have my eye on an even smaller jet, the rumored single-engine, four-seat pocket-rocket from Cirrus Design. (If the one engine fails, pull a lever and a parachute will float you and the plane to a soft landing.) One of the two brothers who founded Cirrus told me the Cirrus jet would go 300 knots, or 345 miles per hour.

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