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Jamie's avatar

My 18’ switch capsized as well when I slowed and water came over bow rapidly flipping the boat over with four teenage girls and two adults. I’m a very experienced boater and this was very traumatizing.

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Matt Marsh's avatar

Has a qualified professional naval architect done a longitudinal free-surface effect analysis for a BRP Switch outer hull in a partly filled state during a deceleration manoeuver?

If not, that needs to be done ASAP.

My back-of-the-envelope estimate, based on photos and a cursory boat show inspection without real drawings to work from, suggests that if you goose the throttle from idle, hit 15-20 mph, and then immediately cut the throttle, something like 600 to 1000 lb of not-yet-drained ballast water will surge forward. The resulting bow-down moment is on the rough order of 5000 foot-pounds. A boat that can only carry 830 lb of payload is certainly not going to be longitudinally stable under a free-surface shift of that magnitude.

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