Indigo Prop Speed Hit?

[Cool Beans]

How much of a sailing speed hit can I expect if I switch to the indigo? 1/2 knot? 1 knot? 1 1/2 knots? I have a Martec folder that is off the boat and needs to be refurbished. Price of refurb is comparable to a new indigo. . .

I was thinking I could refurb the martec down the road and swap em. . .


but, just curious right now. I have a Ranger33, which currently sails pretty quick in light winds. . .6+ knots in 10-15 mph winds close hauled (right term?)

Thanks!!

[romantic comedy]

I think this is a very hard question to answer. How do we know?
I have a tartan 34 with an Indigo prop. I never felt a difference either way when I changed from a 6X12 2 blade. I will say that the Indigo prop is tiny. I was surprised.
I remember in Dave Gerr's prop book, he had formulas for prop area, and I think drag. Maybe that would help theoretically.

BTW I love the prop.

I will be watching the responses.

[Cool Beans]

I think this is a very hard question to answer. How do we know?

Well, I was kind of hoping people with similar boats (long/skinny, light, spade rudder, fin keel, mast head, etc.) would tell me how many knots they make in what kind of wind.

A formula could help if I knew how to properly apply it, but personal experiences may shed more light

I have scaled a couple pics off the internet, and the blade area doesn't seem to be more than say, me dragging both my hands in the water. . .it doesn't seem much, but I didn't want to be startled when say. . .I find out I can now motor faster than I can sail, lol

[Dave Neptune]

Well well well

Cool, you are asking a question that requires side by side performance comparisons. I do and have done a lot of sailing and racing and could not possibly answer accurately. However I can say this I have tried many props on my E-35 MKII and I certanily like the Indigo the best. As far as drag is concerned I do notice that the boat is a "bit" faster with the Indigo over all of the others I have tried, this was done without any other 3 baldes. The indigo has less drag than all of the 2'blades I tried and with the three bladed prop your boat may just be able to outsail its decreased rating due to the "three blade rating" time advantage. I have a better rating with the 3 and a faster (albeit slightly) boat related to it's rating.

Dave Neptune

[ArtJ]

I think this is a very hard question to answer. How do we know?
I have a tartan 34 with an Indigo prop. I never felt a difference either way when I changed from a 6X12 2 blade. I will say that the Indigo prop is tiny. I was surprised.
I remember in Dave Gerr's prop book, he had formulas for prop area, and I think drag. Maybe that would help theoretically.

BTW I love the prop.

I will be watching the responses.

I also have a Tartan 34 C The original 3 blade prop I had was, I think,, 12 X 7 or 8
When running in a chop, the boat speed would drop to less than 3 knots previously. Now I can push more than 5 knots in a chop.
by the way, the Indigo prop was designed for and on Tom Stevens Tartan 34C originally.
Best Regards
Art

[roadnsky]

Well, I was kind of hoping people with similar boats (long/skinny, light, spade rudder, fin keel, mast head, etc.) would tell me how many knots they make in what kind of wind.

Cool-
I'm gonna say from the fold-up to the Indigo will be a half knot OR less.
I've got a Ranger 30 with the Indigo and I sail 5.5-6K in 12-15 depending on chop and clean-boat-bottom.

The Indigo will give you a vast improvement over the Martec in forward/reverse when sailing with the iron jib, that's for certain!

[Cool Beans]

Huzza!

In an effort to help over come my "analysis paralysis" I think I'm just going to order the danged prop and find out first hand No reason if it doesn't work out that I can't swap it out and sell it

I guess I will be letting yall know of any speed hit I take in a couple weeks

Thanks guys!

[sastanley]

Cool Beans..that is what I did. If you do race the boat, Dave Neptune is right..you get a rating credit from most PHRFs for a fixed prop.

I had a 2-blade prop that I had marked so you could hang it vertically behind the skeg/keel to try & reduce a little drag. Then I went to the Indigo and I honestly did not really notice much difference when sailing, but I was certainly worried about it.

The bottom line is the motor is happier. I know these are sailboats, but the Indigo prop should let the motor run a little more free & less lugging.

[Jesse Delanoy]

When I had my Catalina 30, I switched from a two blade prop to the Indigo, to improve performance in reverse. I really never noticed any difference in sailing speed or performance.

[romantic comedy]

I believe it to be an issue of area. The larger the area being dragged through the water, the greater the resistance. The greater the resistance, the more speed loss.

[Cool Beans]

I called and got to talk to Tom today. He agreed my guesstimate of blade area was similar to dragging both your hands in the water. . .

I went ahead and ordered the prop, I should have it this weekend, and back on the boat next week As long as everything keeps working on the boat, I will report back with some actual sailing speed numbers and wind conditions for reference.

Huzza! And thanks yall

[Cool Beans]

Ooohh. . .prop came in, I might have to start a new thread and post pics so you guys can oogle over it

But I must say. . .it is so tiny! I mean, wow is it small. . .it's like a pretend propeller off a pool toy, lol. . .

Hopefully it will go on next week, I just need to get it out to the prop guy

[Dave Neptune]

Load baby!

Cool, I thought the same thing when I got mine, but it does load the engine properly and around 2400 is 'bout it. It pushees my heavy 35'er fine and that's towing a 10' rowing lapstrake dinghy on all trips. Give it some time as the engine will react totally different at low and intermediate speeds. You won't think it is working, until you pay attention to speed vs fuel consumption. The engine sounds lazy as it is just spinning a bit faster to make the "same" HP.

Patience grasshopper

Dave Neptune

[sastanley]

Now that you have your hands on it, you can see that I think the additional drag (compared to a 2-blade fixed) will be negligible.

Be careful..this exact stage is how it all started for me too.

It started with me all excited about my new Indigo prop and blaming Dave Neptune!

[Dave Neptune]

Again

Sorry Shawn.

Dave Neptune