I raced tunnel boats from 70 to 78. I won a couple National Championships in the late 70s in Mod U and Mod 120..I knew Jim Hauenstein , His brother was , as I remember , a head engineer at Mercury Racing Div.I saw him at the Lake Mead race working on the Arcadian. He invited me up to look it over. I spent a several hours with him. The boat was a tail dragger ( not a conventional 3 point), built by one of the top pro outboard hydro builders. It was built to run on the back of the boat and just float the front sponsons except in the turns.
It had a straight drive shaft running through the center of the hull. 8 outboard power heads each driving the drive shaft through a tooth belt( no gearboxes when I saw it run), 4 on each side . It only had 6 engines running when I saw it. It had blown several spare power heads. A belt would break , the engine rpm would rise till the engine blew with no load . I don't remember Jim driving , not sure he was licensed to drive an Unlimites . But that was 30 yrs ago.
Jim said the hull ran pretty good in flat water when all the engines were running but didn't like the race water with other unlimiteds on the course .
It ran more like a flat bottom then a Hydro. rough ride
I also saw the Texmo run at the Clear Lake TX race. I cant remember the drivers name now ( senior moment ), but I knew him and raced against him also. He invited me over to look the boat over.
The Texmo was Triple outboard powered with 3 big offshore outboards , and every time I saw it run , it came in with one or two of the lower unites broken off from the side loads in the turns. It was just a big outboard Tunnel Boat
I went there to see the turbines run.
BTW , I was at the Sacramento Race at Fulsom Lake also . Mira Slovack won that race . Was he driving Wahoo ?
Dick Roberts
Albuquerque NM