I have done this for about 2 years......
Float bag for 20-30 mins, open bag, take out coral, put it in tank. SPS coral I let slime up for like 30 seconds out of the water before puting them in. Sponges cannot be taken out of the water.
Depending what light it WAS in, you may need to place it near the bottom of your tank to prevent sun burn for a few days.
Dan