Ecco cosa dice Garmin in merito allo Street Pilot III :

"Most Garmin® GPS units are waterproof in accordance with IEC 529
IPX7. IEC 529 is a European system of test specification standards
for classifying the degrees of protection provided by the enclosures
of electrical equipment. An IPX7 designation means the GPS case can
withstand accidental immersion in one meter of water for up to 30
minutes. An IPX8 designation is for continuous underwater use."

In pratica, essendo il Garmin III certificato come IPX7 può stare in immersione
ad 1 metro sott'acqua fino a 30 minuti.

Ciao,

M@rco