Floating safe stamps

Eighty-five years ago "floating safe stamps" (shown at left) were issued by the Netherlands and the Netherlands Dutch East Indies for mail shipped between the two countries.

Letters with this additional stamp were carried in a special safe designed to float and be recovered if the ship sank.

The service was introduced shortly after the First Wolrd War in 1921 because many of the shipping lanes were still mined. The stamps were discontinued in 1923.

For more on various philatelic firsts, click here.