Prop Wash – the Aqua Car

By Paul Miller, Blackhawk Chapter

In March of 2015, my friend Peter Mueller sent me an email with a picture of a very unusual boat listed for sale with the suggestion that we buy and restore it. The listing had current pictures and a few original photos said to be from 1947 or 1948. Mention was made that the hull was intact but it missing the original Continental 125 hp airplane engine and propeller. No other comment was made about the boat or what might be included with it.

We made the purchase within days and within a week drove up to Wisconsin to pick up the boat on a flat bed car hauler. We arrived and looked inside to find it full of parts and trim pieces that were seen in a few of the early pictures from the Milwaukee Boat Show of March 1947. We were also handed a large box and told “this goes with it.” The box contained hundreds of letters and other documents to include receipts, photos, and an 8mm film. We had hit the jack pot! 

Days of reviewing the contents were like Christmas morning many times over. We found a series of letters to and from the engineering company, his patent attorney, boat magazines, the boat builder, airplane engine and propeller companies, and product suppliers of all sorts. This guy kept everything, even a letter requesting return of a hammer he borrowed at the boat show.

Philip Christiansen of Phelps, Wisconsin, had a dream about a new kind of boat. He first put that dream to paper in January 1943 at the age of 21. Philip wrote to A.M. Deering Engineering of Chicago on January 13, 1944 in reply to an ad in Motor Boat magazine. Side note: A.M. Deering was doing the prints for Shepherd Boats of Canada at the time and later worked with Streblow, the favorite Geneva Lake boat.

Deering replied they were busy with government work but could fit it in at a cost of about $65 to $75. by March 24, Deering sent preliminary prints for review that were developed from the “cartoon” drawings Philip had sent to them. The final working drawings were not delivered until late spring 1945.

While Deering was working on the drawings, Philip contacted a Milwaukee patent attorney. An interesting quote from his May 19, 1944 letter: “The writer has had a good deal of boating experience and from this I have gathered a large proportion of knowledge incorporated into this definitely new design… and advice from a field or Naval Architects.” Keep in mind he was 22 years of age. The letter further mentions the instrumentation to include the usual gauge as well as a barometer, cabin heat regulator, variable pitch control for the propeller, and a two-way radio. A metal propeller would “overcome breakage should a wood propeller be used and should some hit water while in motion.” His patient was filed March 7, 1945 and issued March 8, 1949, #2,464,166, total cost $112.

Construction on the boat was held up while Philip entered the military on November 5, 1944. Upon his return, he contacted Hemming Larsen of Menominee, Michigan to build the boat. Construction began in late November, 1946 with a goal of completing it for the Milwaukee Sentinel Sport Show on April 19, 1947. Included in the correspondence were construction pictures and the processed checks paid to Hemming Larsen.

The letters give an interesting look into Philip’s personality with one of my favorite being from the Continental airplane people. Their letter, dated March 14, 1947, states: “We do not recommend or encourage installation of this nature, as from what we are told, there is a tremendous amount of development work involved.” Philip’s reply “I do not relish the idea of buying this equipment not knowing how satisfactory it will prove to be, but have in mind the fact that should it not be the most effective unit usable in my experimental boat I can always resell it at not too great a loss.” The receipt for the motor was $854.53, not including shipping.

Continental sent an engineer to Menominee when the motor was delivered and I have no doubt the engineer told him it would not work. No record is found of what happened to the motor. We gained some insight through letters between Philip and a number of boat magazines following the show.

In one example, Lakeland Yachting wrote to Philip on July 3, 1947, mentioning that they had heard from Hemming Larsen the “trials have proven quite successful.” On July 7th, Philip replied: “The writer does not wish to disclose any figures or information on the new “Aqua-Aircar” at this time. You may hear from me at a later date.”

We can assume this was because the boat did not work. This may be confirmed by the film we found and converted to video which we believe to have been done in the early 1960s and available at www.youtube.com.

The film shows the boat re-powered with a V-8 in the rear with a drive shaft under the cockpit driving a sprocket and chain to the propeller shaft. Watch the video and discover why we named the boat Prop Wash. Bottom line, the boat could not get up on plane before the propeller hit the water. I’m not sure what Philip was thinking about or if he was used to calm water lates of Northern Wisconsin, I do have a copy of the ad to sell the V-8 with “less than two hours of run time.”

Philip never gave up. A letter dated June 8, 2000 to the Wisconsin Society of Professional Engineers requested assistance finding “An imaginative Marine Turbo Engineer to redesign propulsion of a patented prototype boat.” Philip added a hand written note at the bottom of his secretary’s typed letter: “P.S. This is no “Mickey Mouse! Nor is it a “Star Wars”! Sadly he never found anyone to help him finish his dream.

After long thought and consideration, Peter and I decided to restore the boat to its original design, powered by the Continental 125 and propeller. However, due to current FAA and USCG regulations, we are not able to operate the boat as originally configured.

Originally printed in ACBS Toronto Chapter’s “Classicboat” magazine.