Turn the boots inside out, fill them with water and wait.You will have to support the crotch area with a broom handle, or board. You will find the leak. Mark it, and apply a product called Goop. It is a marine type sealer, comes in a large tube and is less expensive than Aquaseal...... and it works. I purchased a tube at Lowes.

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There's lots of pretty girls in Mozambique, and there is time for good romance.