A Carnival Corp board member has shown confidence in the reeling company's future, having boosted his stake tenfold.

Randall Weisenburger, a non-executive director of the cruise giant since 2009, spent $10m on buying 1.25m shares at $8.00 each, a regulatory filing said on Tuesday.

The move takes the investor's stake from 125,352 shares in New York-listed Carnival to 1.38m shares.