Just researched about travel to hawaii on f-1 on http://www.fandm.edu/intstudents/travel-instructions
"A valid I-20 Form endorsed" is my guess the 3rd page of the I-20 with the signature of DSO, which would be a sort of re-entry authorization. We don't have such signature on the back of I-20Travel to Puerto Rico, Hawaii, or the U.S. Virgin Islands
A valid I-20 Form endorsed within the last 12 months by a Designated School Official. (If you are on OPT, the signature should be no older than 6 months.)
Valid passport INCLUDING the I-94.
"INCLUDING the I-94.": since we will get I-94 in Hawaii, we will need this when entering the mainland.
Not sure if we can make it to Hawaii without the signature of DSO, or can we?
I really hope this works out.

