Sprouted coconuts are quite inexpensive in Miami. Rather than possibly wasting your time and effort on nuts that seem like they may not be viable anymore, go out and buy some sprouted ones. Try to find a dwarf variety; the talls get big so fast and one can't reach the nuts.

http://www.ars.usda.gov/is/pr/2008/080529.htm

If they've still got water in them there's a big chance they'll still be okay. Go ahead and plant them. Just lay them on top of the soil with the flattest side down. They don't need much encouragement and they don't take long to sprout. I just throw most of my coconuts into a pile under some trees. Now there's a dense thicket of them growing, some up to 3 metres high. They won't all necessarily sprout, glitches can happen which knock them out. A coconut without the sound of sloshing water when shaken will be one of two things, either dead, or else already started to sprout.

Thanks. I just planted them. We will see what happens. If not, there are plenty of coconuts to replace them :)

Hi
IME . I've had the best luck with the largest nuts and those that are immature will have a distinct sour smell
Depending on the weather I've had them take as long as a year Usually you can tell when they go bad as they rot rather quickly while those that will sprout remain firm seems to apply to most palm seeds at least those I've tried. good luck gary