How Fast Does Your Boat Motor?

[TooCoys]

Originally Posted by Sailmonkey

if you were motoring out the kemah channel and the tide was running in, the standing waves by the boardwalk will make all but the longest highest powered and heaviest sailboats crawl through. Also, even though your prop was scraped two weeks ago, it's still not that clean when you consider the extremely low pitch and the low power of the engine. even the slightest growth on there will will cause you to be very sluggish.

I was. However, more than one boat passed me. Everything from a boat my size, to 40 something foots. It probably took 10 minutes or better just to get from under the bridge to the first marker.

[Deltasailor]

The prop is very dirty, it should be shiny bronze. A good clean of the hull would help also. Without anti fouling barnies can grow very quickly.

[TooCoys]

Lots of good points raised, so thank you guys very much.

We are preparing for a trip to St. Maarten for a week, so when I get back I'm going to put it up on the hard and have the entire drive train checked. Cones, shaft, prop, the packing thing, etc etc etc.

I just uploaded the best video that I have of when we were sailing. I have no idea how fast we were going but you can see that we were making good time. It motors at about 1/4 of that speed.

https://www.youtube.com/watch?v=JTB3PHWw5CM

Also, I have been researching the Yanmar manual, and on page 12 it shows a tach sensor. So I took a photo of my engine today, and I believe I have one. The wires coming out of it are orange and blue. On the other side of the harness, I have this disconnected plug, which also has orange and blue wires. I'm wondering if a tach would be as simple as plug and play.

[Sandero]

Depends on conditions.... flat seas (no wind) clean bottom, not towing a dink... 7.5 or so.... motoring into chop and 15-20k with fouled bottom towing dink with fouled bottom... 5 maybe

[kmacdonald]

My Capri 22 will go 5.5 kts with a 4HP Tohatsu 4-stroke. I cruise it at about 4.5 to 5 kts.

[Boatguy30]

Loaded for cruising I make about 5.9 knots on 34' cat with a 8 HP outboard max. Usually cruise around 4.8 or so. Usually sail at 8-9 knots in 15-18 knots of wind so I prefer to concentrate on the half full side of things. Sail probably 85% of all trips

[akprb]

No, from being probably out of alignment and bending on several point. We experienced the same and finally the shaft broke off of St Kitts.

Cheap insurance.

[hsi88]

Another vessel to compare with. My Catalina 27 (about the same displacement) did 5+ knots (GPS) against a weak Chesapeake current (was headed due North) with a 5 HP four stroke Coleman outboard with just under full throttle.

[Scot McPherson]

I don't know why people think your boat is under powered. It might not be enough power for quick maneuvers at dock, but it should be plenty to keep the boat moving along in reasonable water. My 6hp outboard is enough to push my 23 foot seasprite. My 33 ft boat has a 21 hp westerbeke, and that _way_ more than I need to keep moving forward an average of 5 knots and maintaining steerage in 8 ft seas.


While at dock and while idling, put the boat into gear and see if it's pushing water. If the transmission is slipping, on a calm day (zero breeze) you should be able to tell by looking at the prop from the dock if the water is clear.

[Rick Williams]

I had a Bayfield 25 for years with that same engine. On the "test drive" and shortly after I bought the boat she was a real dog under power. I thought we were dragging lobster pots or possibly a mattress with lots of black smoke to boot. I went over the side and cleaned all the barnacles off the (three bladed) prop and the performance improved substantially.
Of course once the barnacles were chipped off the coating was gone and they came back promptly but at least we knew the engine/drive train/propeller were properly sized and viable.
I'd look into the prop size first. The little two bladed deal you have has a lot less resistance under sail but I would think a lot less thrust under power and the prop has to be really clean!
Good engine but needs lots of continuous TLC as I believe it's a raw water cooled. Mine was anyway.

[Nucdad1]

I have a S2 27. 1gm10. @ 3400 rpm clean hull 6.4 knots no current. Martec folding prop.

[Soton]

If you have a rev counter you will know that you were getting full revs. If not I would first try to determine if you were getting full revs. Could be as simple as a stretched throttle cable.

[Three Sisters]

I can suggest checking the transmission fluid. And starting a mechanical log. You've been researching the engine manual so the type of transmission fluid should be listed.

Something like one of these could work as a temporary log.

[TooCoys]

Maybe I just don't know what 4 to 5 knots feels like since I've never been on a boat that moved that slowly.

Today while I was on board, my dock-neighbor showed up and said "are you the owner of Aquaholic?" I replied and said, "Yes but I promise I'm changing the name very soon!"

As it turns out, my boat is back in the exact same slip it was in a few years ago, and he knew the boat. In fact he knew the last three owners. I gave him my contact information and asked him to have the oldest previous owner contact me, which he did.

The PO (three owners ago) told me that if I was going against a current, or high seas, about 2 knots was all I could expect, and that he thought it was slow and underpowered as well. He did suggest that I look into a three blade prop, which he would have done had he not sold it and moved up to a bigger boat. Otherwise, he said it cruises at about 4 knots in good water. I still think that's a little slow, but at least I know I'm not the only one who noticed it.

I also found out that it was once sailed from Alabama to the Dry Tortugas, and before it was brought to Galveston, it had been in fresh water in Lake Travis near Austin.

I've learned who the 4th previous owner was and I've contacted them to get more information on it, and see what kind of modifications they made.

I'm going to take a friend out on Friday and see what his thoughts are on its motoring speed and whether or not he thinks I should keep, or cancel my appointment to have the transmission checked out. He's a bit of a boat mechanic himself, so I trust his judgment.

Maybe I just haven't gotten the "power boat" out of my system yet...

[Hunter33]

I get 6knots with my 2qm20 Hunter33
10500lbs