it just means that it's not saturated with water. give it 24 hours and it'll rise to the surface. at that point put it in a moist paper towel and a dark area so that it'll germinate.
moist paper towels, with a regular cloth kitchen towel to hold moisture in, and put it on your stereo or some place warm.. to hold in moisture and heat even better, put a plate on top of the plate you are using to hold the towels, and it will hold in the moisture, just be carefull removing the top plate, as beads of water will grow on it, and you dont want to dump it into the stereo or TV... so take it off ... max ive ever spent was 5 days, put em in the dirt after the small tap root shows, and it will be out within 3 days after that...
i used the shotglass method (i had some bag seeds that were 2years old), make sure it has alot of heat and darkness (i placed a bowl over it with some hand warmers) and keep an eye on it after 24 hours....i germd 3 and 1 sank (didnt sprout) 2 floated but one 1 of the two sprouted....not saying yours is not going to sprout just letting you know my experience