I have a problem with my tantrum. I can do the tantrum fine have been doing it for years. But the line always seems very very tight, also i have never been able to do an indy tantrum i have no idea why. And anytime i have tried a whirly way to much tension on the line and ideas will help.
Try letting off your edge earlier, around the spray is usually where I start to let off. You may be edging too long. Also try to take it straight up, make sure you get off the wake before you throw your head back. That should also help with grabs.