Agree about checking the drive and steering for excess play. Ideally, you shouldn't have any movement when you try to push the drive from side to side. I think hydraulic steering is nice but overkill on a single engine 60-70 mph boat.

Try using different tab settings, some boats will run better without the hinderance of tabs making the problem worse. Establish a speed where it feels unstable and play with tabs and wheel at that speed then move up a few mph and keep playing.

Never try to drive through the walking, pretty risky stuff. Learn to control it instead. Try sharp but very small movements on the wheel in both directions, it sort of makes the boat do what you're telling it to do rather than let it slap against the water and bounce from side to side. Wiggle the steering wheel.

If she starts to feel a bit loose, you can pull into a very gentle turn to push the hull against one side and stabilize it then slow down to a safe speed and start again.

Just because a boat chine walks doesn't mean it's a bad boat or the set up is wrong, many boats need practice to drive at speed. Learn slow, don't take crazy risks.

RR

One easy thing to check, don't always trust your trim tab gauges. With the boat on the trailer, set the tabs level with the bottom of the boat. Stand back and have a look or put a straight edge up against them. Then look at the gauges and see what they say.

This is your 'level' point, make a note on the gauges with tape or a marker if they aren't reading the same. If your tabs are adjusted differently, could throw a few things out of balance at speed.

RR

High speed wiggle? Dam, I thought this was about Fountain Skanks!

Padraig

that could make things worse quick, getting the rear of the boat higher could cause bow steer in the chine walk situation. and hook that boat around. Play with props and drive height, and check the bottom for hooks or rocker. Also having too much pitch prop and not running in the meat of the RPM range could cause handling problems

Plus 1 on checking the tabs. I was having some problems using my tabs. A buddy of mine suggested that I check them with a straight edge while on the trailer. Well they were off. Port side tab at 6 dots,starboard side tab 4 dots on the indicator. That puts them level with back end of the boat. I now run them at 5 and 3. All good. I have a 21ft superboat with a 509 efi. Full hydraulic steering. Its a drivers boat for sure. I was running a bravo 28p pitch. What my buddy noticed was the prop was actually lifting the back of the boat. I had the blades shortened from 15 1/2 to 14 7/5. Made a world of difference. Hope this helps.

If it's a wiggle and not a wobble you should be fine.

Thank you all. I had a smooth lake and was alone Monday. Spent a bit of time playing around with it. Tether on and life vest of course. I'm a little embarrassed to say this but..... I think it's mostly my inexperience. Here's why I think that. After a bit of experimenting with a little progress. I decided to eliminate things one at a time. All logical like. When the boat would start the "wiggle wobble" I took my hands off the wheel and the throttle. And it went away!!!! Apparently the boat can drive better than me!!!!
I'm thinking I'm prolly white knuckling the wheel when it starts. Damn I feel dumb.
I am going to check the things suggested. And try the additional tips tomorrow. I will get good at this at some point. I am really enjoying the boat and learning. I truly appreciate all your help.

Thank you
Mark

WORD of advise - Don't EVER take your hands off the wheel unless you are at no wake speed. OH and the same goes for the throttle. I had my boat do something real strange and if I had not had my hands on the throttle and wheel I would have been in the trees. I was running a river making a long sweeping RH turn and the boat suddenly turned R.
I chopped the throttle and turned L and drove out of it. I don't know what a hook feels like but the rear of the boat didn't slide out - the front just turned. I am learning how to drive this boat all over again. I was by myself and was driving aggressively but didn't think I was that out of shape.

Things happen with different passenger loads and previous experience. Back in 1957 I had a buddy that made multiple passes through a 'wiggly' channel by himself at full speed during daylight. So he loads the boat up with his beer drinking buddies (me included) and makes this pass at night. Guess what happened? The engine must have been at 15,000 RPMs when we were upside down crashing into the water missing the first curve. The motor stopped real quick when water entered the intake.