Atomic4 Testimonial Page

Propeller Comments:

C&C 32 - "Hi Tom, Thank you for your help. The propeller arrived with plenty of time to spare and is much smoother than the 2 blade it replaced and seems to let me cruise comfortably at a higher speed. and the motor sounds a lot happier at higher rpms now. Thank you."Chris Walter - Richmond, BC - September 2023

Alberg 30 - "Hi Tom. Moment of truth will be tomorrow am at 8. Hi Tom, very happy to report a huge success! Boat runs like new. Thank you so much for your support."Nick Allinson, - Kingston, ON - June 2022

Catalina 30 - "After a lot of research, I purchased this propeller, shipping was quick, installed and took our 1st cruise of the season May 14th, 2021. WOW !!! What a huge difference. My wife commented " Sounds like a completely different engine". I found this prop greatly reduced engine and prop noise. Ran very smooth. The performance at lower RPM's was excellent. Just as you stated. While I don't have a RPM guage, run by sound, I immediately noticed I was barely half throttle, maybe 40%. I was running easily 6.0 to 6.50 knots with out the engine running fast as it used to. Hit a nice sweet spot and was able to cruise at a respectable speed without out laboring the engine. Further, and the primary reason I purchased the propeller, was greater control in and out of the Marina. Again, another huge difference. Prop walk was reduced and reverse momentum greatly improved. I actually under shot my first slip docking. I knew from my previous prop., what distance I needed to engage reverse in order to slow the forward momentum coming into the slip. Out of habit, I engaged reverse as usual, immediately begin slowing and actually stopped well short of the slip. That never has happened before. I am extremely satisfied with this propeller. It has performed exactly as you said it would. Best $360.00 I have spent on upgrades. In case you post this as a testimonial, I am running a 1983 Catalina. Standard rig, winged keel. Engine is a Atomic 4 30 H.P. The old prop was a Michigan Sailor 2 blade 12RH 7. Prior to purchasing, I checked with everyone I knew or could find to talk about changing out props. Everyone as usual had their own opinion. Ranged from definitely a good upgrade, to "no way" doesn't matter, a three blade prop. doesn't change anything. Save your money and upgrade something else. Believe me I heard it all. So was I skeptical, sure. Couldn't find 5 people to give me the same answer. After our 1st cruise, May 14th. 2021, Green Bay, WI. to Cedar River MI., about 10 hours, mostly on engine, I am very glad I listened to my own good instincts, and purchased your prop. I highly recommend this to anyone looking for a good upgrade. Made all the difference for me. And did I mention fuel consumption? I have a 18 gal. tank. When I arrived at Cedar River Mi., just barely over a half tank used. Thank you."
John Rovinski Cedar River, MI - 2021

Newport 27 - "Finally got the couplings back together (after a new rear main seal was installed) last weekend and took the boat out for a sea trial. Used to be I would get around 5.5 knots at 1800 to 2000 RPM. With your new prop, the RPM at WOT is now about 2400 to 2500 RPM in flat water and with minimal breeze in the LA harbor, the GPS reported speeds of 6.3 to 6.4 knots on my 27 footer. That is the best speed ever running on the iron wind only and I have owned this boat for 7 years. Your prop is delivering better speed with much less vibration than what I was getting out of my old two blade 12 x 8 prop. The absolute best part is when backing out of my slip, I had virtually no prop walk. The boat went straight back and when shifted to forward, the stern stayed on track. Sweet! The one thing I will have to get used to is that the increased wash over the rudder at WOT has made weather helm much more pronounced. The bright side is that at cruising speed of 1800 to 2000 rpm, the weather helm is back to what I would consider to be normal. BTW, A few years ago, I installed your PCV kit and it has killed off my oily stench in the cabin problem. That upgrade made life in the cabin bearable when running the motor for long periods. Thanks for the great products Tom!"
Chris Pechon, Fullerton, CA - 2015

Ericson 35 E-35 MkII s/v Volador, 1970 original A-4 still ticking!!!- "I used 3 different diameter 2-blades 14, 13 & 12" before and I could tell the light air performance was off with the two larger diameters however not much. With the Indigo 3-blade I could tell very little differance in fact if anything I think it has less drag than any of the above since the blades are very narrow. I really didn't notice any sailing performance differance with the Indigo however everything is MUCH better while motoring especially in reverse and there is almost no wobble in the tiller like with the two bladed props! I wish I'd found the Indigo 26 years ago when I started playing with props. I used the 3 diameters above and each one was re-pitched a few times as well. The 13" was actually the 14 cut down."
Dave Neptune, Santa Fe Springs, CA - 2009

Catalina 30, 30' LOA, 25' LWL - "I switched over to an Indigo 3-blade prop from the original 2-blade on my Catalina 30 about five years ago. I'm a cruiser, and I don't cut my performance numbers too fine, but I haven't noticed any particular decline in performance under sail. Backing into the slip is much easier than it was."
Jesse Delanoy, s/v Off The Grid, Baltimore, MD - 2009

Ranger 28, 28' LOA, 25' LWL - "Your 3 blade design is the way to go. For the first time, we have a versatile RPM range that allows idling in gear, accelerating or stopping under power. Reverse handling is a huge improvement ... your Atomic 4 engine upgrades are improvements that will benefit any sailboat owner. Performance and peace of mind from a company that could not be any easier to deal with is a tough combination to beat."
Walt Hodge, Stone Mountain, GA

Ranger 33 - "I just installed the prop you sold me for my A-4 powered Ranger 33, works great! At 1700-1800 rpm I do an easy 6 to 6.2 knots in calm water, it seems to provide a lot more uumph in reverse also. Sailing in light air this weekend I did not notice any difference in sailing performance. I think I'm going to like it!
Scott Susoeff , Redondo Beach CA

Catalina 30, 30' LOA, 25' LWL - "Great ahead speed, good reverse, and no vibration at all. I am delighted."
Mike Gulla, Hampton, VA

Yankee 28 - "You can add the Yankee 28 to your list of happy customers. Every boast was met and we are very happy with all aspects of the prop. We have increased rpm, speed, charging, oil pressure and decreased engine temperature."
Greg Bowlin, Arlington, WA

Tartan 30, 30' LOA, 25'LWL - "The prop was simple to install without the key configuration. I found that reversing out of the dock was wonderful (no walking) even in a side wind I was able to control the boat just fine. Docking and getting around the marina, the reverse stopped the boat very well. Cruising speed I gained almost a full knot of boat speed. Sailing, I lost less than 1/4 knot of boat speed. I recommend the prop to any cruiser with an Atomic 4 engine. Hard core racers may want to look for something else of do what I do, jump on someone else's boat for the race and come home to a comfortable boat to rest."
Bill Gunkle, Toledo, OH

Columbia 8.7 - "Prop is wonderful. It is like a different boat under power.
Nelson Stone, Yankton, SD

Columbia 8.7 - "The performance of the prop is outstanding. You have done a fantastic job of developing it. Our boat can motor at 6.5 knots with out even pushing it, compared to a 12 by 6 pitch prop with a top speed of 5 knots at full power. I also have not noticed any additional drag while under sail as was originally feared."
Tim Killian, Stratford, CT

Columbia 8.7 - "We replaced the 12x7 with indigo after our first year of boat ownership, mainly because of reversing issues, but it was actually probably mostly our inexperience with an inboard. When tested first time my son said, "cool, I can steer in reverse" as he did figure 8's. Forward is as claimed by Indigo - less vibration in tiller and boat, smoother operation, feels like the A4 is loafing, etc. Stopping seems fine. A couple times the few second burst of reverse actually reversed direction instead of just stopping the boat. That looked pretty sillly! Prop walk is much reduced also with three blades."
Jim Booth, Cary, IL

"Vixen" 39'-9", 9.5 Tons Displacement - "I've been meaning to write to you regarding your new propeller for the Atomic 4. First of all, thanks for your quick response to my cell call/voice mail message placed last Sept. We were on the Chesapeake, sailing into Annapolis, when we hit a submerged log and broke the blade on the CDI prop( plastic). In that it was the 3rd CDI in 6 years, I felt it was time to go back to a metal wheel. Your response to my call was a lifesaver ( actually a cruise saver). As to your prop, its great! It gave VIXEN 1 full knot. VIXEN is a wooden double ender built by Ralph Wiley in 1955. She is 39'9", beam of 9', with a full keel, and a displacement of approx. 19k. Yours is the first prop that will bring her up to, and cruise at hull speed under power. Plus she even backs up in a straight line. No more prop walk. I am more than pleased."
Paul Delatush

Ericson 27 - "just got the three blade installed! wow you wernt kidding! works as advertised and beyond! opened up throttle leaving yard, and my ericson 27 went to 6.5 knots like shot out of a cannon, into the wind and seas! throttle back to an easy lope and she was chugin at 5.8 knots. never got over 4 knots on a good day with the two blade 10" sailor that came on boat. i will spread the word!"
Robert Peacock S/V Kodachrome Rockport, Tx

Ericson 30 - "Just a note to let you know how satisfied I am with your propeller. I was one of the first purchasers of this prop several months ago, but didn't have a chance to put it through its paces until recently. I moved my 1968 Ericson 30 from New Jersey to the Chesapeake Bay, motoring most of the way. I've also gone sailing several times since then. It moves the boat at hull speed (about 5.5 knots) at about 2,300 RPM, and reverse is much improved (my prop shaft is offset to port, so you can imagine how much fun backing is). Thanks for making a fine product at a reasonable price."
Max J. Sandler, Monroeville, NJ

C&C 35 MkI - "More speed, less noise, less propwalk. We are very happy so far. I can do over 6 knots pulling the 10 foot dinghy into a 15 knot headwind and some chop. Noise and vibration are MUCH lower. There still is propwalk, but not as much. Overall a HUGE improvement over the 12x6 two blade.
Joe Della Barba, Stevensville, MD

C&C Corvette (3-4" Deadwood)- "I've just completed a four day "test cruise" of the Indigo propeller. "White Wing" is a 1968 C&C Corvette sloop with Atomic Four propulsion. The Corvette has a very small aperture, which limits prop selection. The previous owner was using a 11 X 7 two blade that left only a quarter of an inch between the blade tips and the hull. This created a very unpleasant noise and lots of vibration. The engine would rev high enough but there was a lack of power. I spoke with Tom Stevens, who was familiar with the Corvette. He assured me that the three blade prop would make a vast difference. I recieved the new prop (via overnight shipping) and after changing out the old one, started the engine. With dock lines still attached, I slipped her into gear and held my breath. What's this??? The only sounds I heard were those of water gushing from astern and the squeaking of strained dock lines. Later, I backed out of my slip and actually had control of the boat. Motoring with slight tide in the I.C.W produced a glorious 6.7 knots under full power. Crusing RPM (1750) yeilds about 5.5 knots. My overall RPM's are a tad lower but the thrust is very efficient. Low to mid throttle range is responsive and economical. There's not a diesel around that can run this smooth. I noticed no difference of drag while under sail only. Motorsailing while charging batteries is fast, quiet, and will give great gas mileage. The boat just seems to be less bound up. Combined with Indigos' Crankcase Ventilation Kit, White Wing is now a smokin, smoke-free sloop!! THANKS INDIGO!!!"
Kevin, New Smyrna Beach, Fl

Islander 37- "I bought one of your propellers about a week ago. I gotta tell you it is a fantastic product. I am 100% satisfied and then some. Excellent, excellent work. ... Once again, a fantastic propeller, super happy with it."
Dar Bartkis, Chicago IL

Tartan 34, 34' LOA, 25' LWL- "We got a really late start to this season, but I've just taken Insight out for the 5th time, yesterday, and have to say that Indigo's 10" x 7.4" 3-blade replacement prop for the T34 is working better than predicted. Previously (with the original 2-blade 12 x 9) the high end RPM's was 2000; now it's 2800! The engine no longer has any burning smell emanating from down below (cooking oil on top of the block, electrical wire insulation, etc.) and is running decidedly cooler. Boatspeed under power is definitely up, although I still have to compile more numbers on that for confirmation. Boatspeed under sail is unbelievable. We hit 8.1 kts recently in 1-2 ft. seas, 15kts on the beam and no current. First time I've ever seen anything over the middle 7's! Initial forward thrust/speed is very impressive, turning radius's have decreased considerably and control and speed under reversing situations is markedly improved. I can't say enough good things about this prop and highly recommend it to anyone with the T34 and A-4 engine. It feels as though this boat finally has the auxiliary power it needs to kick ass in any situation. We have an impossible cross-wind docking situation (with the dock upwind and pilings downwind and no water 10 feet in front of the bow) with no room for mistakes or maneuvering and yesterday I finally achieved a perfect docking, which I attribute to a lot of practice and research and, more importantly, the improved maneuvering control I get with this new prop. I can shove it into reverse and, with a quick throttle burst, get Insight's rear end to swing right over to port now. With almost no forward way on I can put it into forward and goose it just slightly to get steering control again. Wonderful!!!!! RC Insight II 1970 #136 E. Falmouth, Cape Cod, Massachusetts
RC Insight II 1970 #136 E. Falmouth, Cape Cod, Massachusetts

Cal 29- "Tom, I should have sent this after I installed the prop, just never got around to it, so here goes: Installed, replacing a standard 2 blade bronze. Yard guys were unimpressed, they said it looked too small. We launched and got ready to depart for the harbor. When I put the shift in forward it was just smooth, we accelerated to about 5 knots and were on our way. But the most amazing thing was I could let the wheel go and the boat kept going straight! The 2 blade always pulled to the right, and by the end of a three hour trip upriver to Lake Michigan I was tired from just trying to keep the boat on course. Now the trip is actually fun! I will be pulling the prop next week so I can send it to get modified to be even better. Thanks"
David Dobbs, Cal29, Chicago IL 2015

C&C 29 Mk I- "Tom, I have a 1977 C&C 29 Mk I - with your prop I make an average of 6.3 knots at 1800 RPM, burning about 1/2 Gallon a hour, no vibration very smooth. My boat is approx 9000 pounds loaded. In reverse, I am able to manouver to starboard now, while previously I was dragged hard to port (like most C&Cs around my size, I have an offset prop). Plenty of thrust to slow her to a stop when approaching a dock.Looking forward to the crankcase vent kit, as I have some crankcase fumes in the cabin right bow - the original scavange tube has a crack in it, which makes a poor design even less effective. Thank again, Chris "
Chris Saunders, C&C 29 Mk I, Thunder Bay ON Canda 2017

Upgrade Kits:

"Tom, I've been running the motor and am amazed at how well this system has dealt with the smell. Not only that, but the motor is running so much better than before - I couldn't get it to idle low previously, now it's idling so low you can barely hear it running! I must have had a vacuum leak somewhere in the system that this has solved. Amazing product. Thanks Tom." Nick Allinson, Alberg 30 - Crankcase Vent System - Kingston, ON - 2022

"Tom, I just wanted to let you know I got the electronic ignition installed today on my atomic 4 engine and it worked perfectly. I cannot thank you enough for the detailed instructions. It made the job much easier than it should have been. You can definitely count me among your satisfied customers, and as I continue working on my boat I very well may be interested in some more of your products." Des Stevens, New Horizon 26 - Prestolite Ignition, Rushville, IN - 2020

"Thank you Tom! I appreciate the quick response and personal attention that you gave to me over a small order! The parts arrived overnight, and I was able to quickly install the new electronic ignition in under an hour. The boat started right up and ran great. I can't tell the difference between this EI and my old Pertronix EI, but I am more than happy knowing my ignition won't burn out when I inadvertently leave the ignition switch on. Again top notch help, and a very easy to install ignition system. Thank you" Jim Homet, Tartan 30 Ignition, Portsmouth, NH - 2020

"This is a shout-out for outstanding customer service from Tom Stevens at Indigo Electronics, a purveyor of aftermarket accessories for the venerable Atomic Four. Last fall I purchased an improved cooling circulation pump from Tom, but hadn't yet installed it. Recently Tom emailed me to say that he had become concerned that my pump might be part of a bad batch and could have a potential reliability concern; and could I please return the pump to him to test? I did, and it checked out fine, and when he promptly returned it to me he had even upgraded some of the hardware, all at his own expense! Customer service just doesn't get much better than that. Kudos to a first-rate provider." Warren Stein, Leesburg, VA - Writing to Practical Sailor - 2020

"Just to let you know, I installed the PCV kit on the Atomic 4 in my Pearson 30. This engine has some pretty intense blow by that caused smoke from the breather cap to fill the cabin with noxious fumes. Installation of the new valve has eliminated this situation completely. The kit was easy to install taking less than an hour. Thanks again for supplying such a great improvement for this fine old engine. "
George Barnett, Mays Landing, NJ - 2009

"The PCV valve conversion, made by Indigo Electronics of Newport News, VA., is a fine package of well-made parts and clear instructions. Installation took about an hour, and our engine never breathed as clean as it does now. There are no more fumes in the cabin."
Tom Dove, Chesapeake Bay Magazine, July 1996

"I have installed 2 of Indigo's kits (Electronic Ignition and the PCV system) with excellent results. The value of an electronic ignition is a no-brainer, particularly when getting to the points is next to impossible as mine are. The PCV installation completely eliminated all of the fumes in the boat and was easy to install."
Larry Dow, Eliot, Maine

"The system (electronic ignition) is working great. My atomic 4 runs better than it has for as long as I can remember. I intend to change to your electric fuel system also in the near future, and probably to the fresh water system also."

David Mize, Tustin, CA

"The installation was straightforward and simple even though the Newport 30 II "engine room" requires that the distributor be worked on through a 4 inch high gap between the hull liner and the underside of the cockpit. The results? Astounding! After more that 200 hours the engine starts on the first turn and the plugs haven't needed to be changed."

Pat Broderick, Club Newsletter, CA 1995

"Just wanted to give you an update on the FWC I purchased a few weeks back. Well I got a chance to get down to the boat [ it's almost a mile f om home]. I made up an extension for the alternator bracket, got a couple of hose fittings and adapters, tightned everything up, flushed the block out with fresh water, followed your instruction regarding filling the antifreez and fired it up. Runs great, seems a little quieter and smoother than before the kit. I then changed the oil and winterized it. Overall I am very impressed with the quality of the kit and the instructions that came with it. Every thing fit and worked as advertised. Thanks."

Andre Weiser, New Rochelle, NY 1999


To order your's today, send check/money order to:

Indigo Electronics, Inc.

105 Pipe Kiln Court
Williamsburg, VA 23185

Order Today. You never knew sailing could be so much fun!
1-800-428-8569 toll free
or 757-593-8569

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