How long copper sheathing lasted and why crews benefited

Did copper sheathing fall off after only days or weeks?

No. Numerous copper fastenings held it firmly in place, and it could last a long time despite damage from storms.

The illustrated wreck retains copper sheathing after much of its wood has disappeared. Numerous small copper fastenings held the plates in place, so they did not ordinarily fall away after days or weeks. Storms could damage them, but the protection lasted long enough to reduce repeated hull-cleaning work. The Royal Navy's expenditure on coppering helped ships operate with smaller crews than French counterparts and gave sailors time away from maintenance. Reduced fouling also preserved handling and maneuverability.