The SATA cables that have either come with mobo's, or I've picked up later (when I added another pair of SATA drives) were 18" long.
What are you connecting to that is 3 meters away from your rig? Seriously consider putting that drive into an enclosure with either FireWire 400 (or 800) or even USB2. Those have MUCH longer maximum runs. I think I've seen 5 meter FireWire cables before, maybe even longer.