Efficient speed

Good question. No expert here, but I would guess the most fuel efficient speed is just past the point that the hull get on plane. Make sure you stay out of the secondaries.

Really, you commute to work via boat? I had that opportunity just recently while I was building a lake house for a client. But never did the commute via boat because of the added time involved. The lake house was on the same lake that has a public ramp less than a mile from my house.

Yep, CC's are semi-displacement hulls as opposed to planing hulls. This means it takes a lot of power to get it on plane and keep it there. I usually cruise around at about 2700 rpm or so.

I have a different opinion about the semi-displacement hull. I think that a CC is a planing hull. I see a trawler type hull as semi-displacement. a CC takes far less power to run a slower speeds that an outboard or I/O powered boat. The placement of the engine closer to the midpoint of the hull keeps the bow rise down. Check any performance info for an I/O or outboard and you will see fuel economy is very poor until the boat comes onto a plane usually in a range of 18-20 MPH. Boating magazine is a very good reference for fuel economy as they publish reports for many different setups. I would guess that your martinique would consume somewhere in the range of 6 to 8 GPH @ 28 MPH ~ 2800 RPM. therfore you would be around 4.7 to 3.5 MPG. When I get a chance I will look up some data in my old Boating magazines to see if I can find a similar boat with fuel consumption data.

mandovoodoo wrote: I do commute by boat when I feel like it. Same distance as by car. About 2.5 miles. Temptation to skip work & head on down the lake. I live at TN river mile 608.1 and my turnoff into the cove for work is at 606, Cloyd's Creek. Beautiful this morning. Just a bit of skimming mist over the water's surface, very smooth, very quiet. Blue herons flying. Geese. I back away from the dock, get the bumpers stowed, then swing out into the main channel and bump up the speed. Woods on the right mostly, houses and woods on the left. Then a large old farm with a big house comes up on the right and I sweep left into Cloyd's Creek. Today I simply kept on plane at about 30 and slipped up the channel. Very smooth. Nice handling boat. Dropped to idle and ghosted into the slip. Pretty much fun. I carried a bunch of stuff for the shop, a bike and a box to ship to my brother and so on. Easier than dragging all that junk up to the truck! I'm amazed at how much stuff will just pile into a 20 ft bowrider.

Read this again in a Humphrey Bogart voice, Sounds like a segway into a murder mystery. I gotta stop day dreaming and get back to work

Good stuff voodoo.

Hmm. I suppose I'm a transplant. Born Seattle 1954. Raised on Air Force Bases in the midwest, lots of time in Britain. About 1970 I started living in the south. Moved north to PA a little bit, didn't stick. 1970s in VA, 80s in SC & Egypt, from 87 on in Friendsville, TN. 35° 46.82'N, 84° 10.28'W I'm right on the main channel of the Tennessee River, left bank.

My shop, Gianna Violins, is on a tributary, Cloyd's Creek. 35° 45.16'N, 84° 10.34'W

I really like the boat. I've had a few powerboats. Clearly too dinky now that I have this thing to drive around. Biggest was a 1963 Norriscraft w/big twin 40 hp Evinrude. The Martinique ("Miss Demeanor") is a very nice stepup. I wondered about driving an inboard, but really no trouble. I've spent a great number of hours in small craft under sail and paddle, and many hours piloting a 40 ft cruiser, although docking that was always terrifying. It wasn't mine. Odd, I have more HP than the old cruiser did!

Gradually learning the Martinique. I checked a stretch of lake this evening then ran WOT for a bit. I don't think the prop is perfect. The engine seems to run well and the plugs look great. But I only got 4200 rpm. The stock knotmeter read 37 mph. I trust the tac! I'll have to check what WOT should get me with the right prop.

Getting into the carb was really a trip. I haven't done that in a very very long time. Figured it out pretty quick.

Actually the ride home was great. Very little wind. Warmed up the boat at fast idle out Cloyd's Creek. Once I could see the main channel I slid up to 3000 rpm then backed off to 2700. Coming out of Cloyd's Creek I can see downstream and upstream nicely and set a slow turn upstream into the main channel, straightening out to pass just left of a red buoy by Clayton's (mobile home guy) place. Then I can set a slight turn the right that finishes at my dock. A bit too quick, so I usually slice upstream a bit and do a bit of poking around before I go home.

This evening the sun was down quite a bit, I suppose it was around 7 pm. The clouds lined with silver. Lots of martins skimming the water, and a few herons. After my WOT run I saw two osprey hanging around the Coulter Shoals light. They nest there every year. We've watched generations pass through there. We also get loons in the lake, but it is too late for them.

Here's the chart: http://www.lrn.usace.army.mil/opn/TNRiver/charts/84.jpg

Tomorrow Calhoun's at Ft. Loudon Marina is open for lunch. I'm going to take Gianna down there via water. Will be fun. Gives me an opportunity to screw up docking in front of people!

Last time I was there I saw a guy back a twin screw cruiser, an older one, into a slip. He stopped the boat six inches from the dock. Stepped off with the lines and tied up. Just beautiful. In contrast to most of the drivers in the funny slick new boats, who often can't figure out how to tie up.

Drop by and visit if you're near the Smokies. www.giannaviolins.com   

I've been up in Norris. Took my batboat (1963 Norriscraft w/outboard. And fins) up there once or twice. If my vehicles would tow the Martinique I'd bring it up, but not quite big enough to do so. I could tow with my explorer if I wanted to swap transmissions on a regular basis!

We serve a rather large bluegrass audience. I hit that unusual crossover point pretty well. I'm classically trained in depth as a performer and am essentially a classical Italian school violinmaker, but I prefer to listen to and hang out with the dark side. I'll even pick up a b*njo at times.

And I do fine with low speed docking etc. I just get concerned. Possibly left over from the very poor brakes on the single screw 40 ft I used to get to drive. At least it was slow all the time!

The chart I reference above shows my house, my shop, and the dam. That's my usual poke around area. I like going up Tellico Lake. Clean and cool. Great skiing in the AM before other idiots get out there.

We get commercial traffic, which is fun. Lots of bass fisherpeople. Most people behave sanely, although few use horn signals. Summer weekends get some nuts out, but relatively few. And law enforcement is keeping the drunks off the water. We had a few killed and they cracked down. Correlated with a decrease in topless drunk behavior.

I'll attempt to remember my camera if we run up to Calhoun's tomorrow. I can hang a web page of images.

Where can I find a plyon to tow the kids skiing??? I suppose I'll just have to look around somewhere.

http://www.giannaviolins.com/vl/gv/CC.html shows my boat at rest at work after driving in.

We went to Calhoun's at Ft. Loudon Marina for lunch. All you can eat $10 including tax & tip. Good deal! I had Gianna back out of the slip and drive us up there. Think she is getting a better handle on things. Showed her WOT performance, did a little better downwind. This thing really likes being wide open, but I think my mileage is very low like that. She made me dock at Calhoun's.

We got reminded at how oddly many boaters drive. Had a good sized ski boat come from our left suddenly across our path. Just stupid. First, cutting in front of us. Second, cutting off a corner out of the channel in shallow water. I've seen a big boat hit bottom in the same area years ago. Had to be towed away, probably did $10,000 damage! There are stumps.

And later, a ski boat changing speed and direction randomly in front of us. Circles, wild starts, etc. I suppose that type of thing is OK, but it is a bit disconcerting to me. I'm used to treating the main channel of the Tennessee as a major waterway to be kept reasonably clear and to behave in. There's plenty of non-commercial byways for fooling around in.

At least the PWC owners are much more polite and predictable now. I suspect our law enforcement folks pressed hard after a number of deaths and other stupid things.

One of my main concerns on the water remains the recreational weekend boater with a new 25 ft SeaRay. Lots of speed,lots of power, only moderate visibility, usually lots of distractions, and no idea about the rules of the road. Because I have no idea what they'll do, they worry me. Also, they no idea how long it takes to stop or turn a tow. I respect the tows. Can't imagine what some of these folks are thinking. I certainly can't hold my breath long enough for a tow to pass over me. And I signal my intentions or clearly move out of the channel when they're around. Hard enough to get up the upper Tennessee without having to worry about small craft!

What foam? How do I check? What do I do?