How bad does smooth water cut your top end?

[kp216]

All right, my boat is not a hot rod as top end with two people in the boat is 55mph. I took the boat out the other evening just before dark and the water was glass. The ride was fantastic, but the best I could do was 46mph.
RPM was the same (4200) and it didn't matter where the diverter was.
I guess I've never really paid attention before when the water was smooth because I usually have the wife and kids in the boat and won't do hard runs. Is a 10mph scrub of top speed common in very smooth water? The boat felt heavy as hell.

[Mandelon]

Did ya put in the drain plug? :D
Don't forget that altitude, air temps, loaded weight and humidity levels play a part as well in motor and boat performance. Any or all could have affected your run.
Also runnin up or down stream (in a river anyway) would show a variance from actual speed unless you had GPS.....

[BUSBY]

"altitude, air temps, loaded weight and humidity levels play a part as well" a very accurate statement.
Usually, smoother water means better runs, higher mph due to the fact that you can stay in it harder and longer (no chop to deal with).
With no data ... and just guessing here from your post ... I would venture to say if you're getting better speeds in chop (or rougher water), you're probably running real "wet" on smoother water. Meaning ... that you boat is riding deeper when it's smoother and not getting enough lift. The "deeper" or "wetter" (is that even a word, wetter?) your boat is at speed, the more drag you'll have. This means when you get a little chop, you'll "air out" a little and RPM's will climb, you not have as much drag, etc., etc., etc. = higher speeds.
Again, this is with no data, but a common problem with a lot of river and lake boats.
If you have a ride plate, lift it 1/2 degree and see what happens, then try another 1/2 degree. play there and then see how "dry" you can get the bottom.
Good luck,
Brian

[steelcomp]

Also runnin up or down stream (in a river anyway) would show a variance from actual speed unless you had GPS.....
Running up and down stream will show a variance with a GPS. Speedo will only show true water speed, weather up stream or down, providing speedo is accurate. Ground speed will be relative to current, and this is what GPS measures.

[Danhercules]

I think he is talkin about runnin on glass. I have the same question. I was on Elsinore yesterday, and on flat glass, the boat just dont seem as fast. I am guessing a little wind chop, not rollers by any means, would be the best.
How much dose weight come in to play too? Like full fuel, 26 gallons.

[kp216]

I think he is talkin about runnin on glass. I have the same question. I was on Elsinore yesterday, and on flat glass, the boat just dont seem as fast. I am guessing a little wind chop, not rollers by any means, would be the best.
How much dose weight come in to play too? Like full fuel, 26 gallons.
You're right Dan. This was a lake, it was smooth as glass and I had about 15 gallons of fuel left in my bow tank, which doesn't help on speed.
I know my boat runs very wet and I don't have a ride plate, droop, set back etc. My best speed ever was 59mph on gps with just me in the boat, about 10 gallons of fuel, running into the wind with about 4" of chop.
I was just really curious if glass lake water had the same effect on everybody else's boat.

[OMEGA_BUBBLE_JET]

my boat runs faster with a mild chop also. In glass I ride very wet and feel 'glued' to the water. Also having a smooth bottom doesn't help much. I have actually seen jetski guys sand the bottom of theirs to help break up the water and help 'free up' the boat. I think speedcoat has the same intended effect.
Omega

[BrendellaJet]

I think all boats are different. I know mine runs wetter in glass. Give me some mild chop and it gets measureably faster.

[cole13]

"altitude, air temps, loaded weight and humidity levels play a part as well" a very accurate statement.
Usually, smoother water means better runs, higher mph due to the fact that you can stay in it harder and longer (no chop to deal with).
With no data ... and just guessing here from your post ... I would venture to say if you're getting better speeds in chop (or rougher water), you're probably running real "wet" on smoother water. Meaning ... that you boat is riding deeper when it's smoother and not getting enough lift. The "deeper" or "wetter" (is that even a word, wetter?) your boat is at speed, the more drag you'll have. This means when you get a little chop, you'll "air out" a little and RPM's will climb, you not have as much drag, etc., etc., etc. = higher speeds.
Again, this is with no data, but a common problem with a lot of river and lake boats.
If you have a ride plate, lift it 1/2 degree and see what happens, then try another 1/2 degree. play there and then see how "dry" you can get the bottom.
Good luck,
Brian
I totally agree here. My boat has a ride plate and a divertor, so I can air it out regardless. However a buddy of mine has nothing and if the water is really glassy it feels like you are driving in sludge. Very weird feeling. But if you add some wind chop it frees up and hauls butt.
Try to add a divertor, it really makes a world of differece, and will actually keep your family safer in rough waters. You can keep the bow up a lot easier!! JMHO

[Squirtcha?]

Although I haven't actually gps'd it, I know my slows down when the water's glass-like.
http://www.homestead.com/jetboat/roostage.jpg

[SB]

Water is "sticky" so a little chop helps the boat air out, and reduces wetted surface on the bottom, making you faster. This is well documented in larger fountain type boats.

[HBjet]

Glass = More surface contact (more friction)
Mild Chop = Less surface contact (less friction)
Less friction is always faster then more friction... even if it's glass!

[OkieDave]

My Cheyenne runs faster going into the wind, especially when carrying extra weight. I took a big guy for a ride once and could only run 85 downwind but the return trip we hit 95. My 26' Firehawk is the same way, wind helps lift which helps speed. gotta watch it tho, it could cause a blowover. :D

[Ken F]

Kevin, as has been said-any boat will run slower in glassy conditions.
Race boats will run their fastest in about 4" chop. Think about all the air bubbles which are created under your boat running in chop-little ball bearings!
Ken

[HBjet]

My Cheyenne runs faster going into the wind, especially when carrying extra weight. I took a big guy for a ride once and could only run 85 downwind but the return trip we hit 95. My 26' Firehawk is the same way, wind helps lift which helps speed. gotta watch it tho, it could cause a blowover. :D
This is true for any air entrapment hull. More air, more lift, less friction, more speed...
HBjet

[HBjet]

For air entrapment hulls (such as a 19' daytona or others like it)
What do you think would be faster/quicker?
Running on glass into the wind or running on 6" chop with no wind?

[Danhercules]

Glass = More surface contact (more friction)
Mild Chop = Less surface contact (less friction)
Less friction is always faster then more friction... even if it's glass!
Ok, we all seem to agree on this. But now, how much dose it affect top speed. Any guesses? 2MPH, 5 MPH, 10 MPH?

[Nucking futs]

6" chop with no wind ..............hands down

[roostwear]

I go my fastest (relative term) with a slight wind chop. Glass can cost me 5-8 mph.

[HBjet]

I go my fastest (relative term) with a slight wind chop. Glass can cost me 5-8 mph.
Don't forget the bimini adds lift! haha...

[HBjet]

Ok, we all seem to agree on this. But now, how much dose it affect top speed. Any guesses? 2MPH, 5 MPH, 10 MPH?
Too many variables to make that guess.

[roostwear]

Don't forget the bimini adds lift! haha...
True. Maybe glass slows me down because it's normally early in the morning. And in the morning, the cooler's full. In the afternoon, the wind chop comes up and the cooler's lighter. Well hell, thaere's the real speed secret.... you have to drink the cooler down for less weight!

[Kindsvater Flat]

5-10 mph depending on water.

[flat broke]

Damn,
Guess I shouldn't have torn the Spectra down.... The last speed numbers I got on it were from elsinore on glass water. Could only pull 72mph. I had Cyclone, Tyson, and 3 other passengers in the boat comming back from the Sandbar at the CBBB and they both said it felt like an easy 80-85mph. I sure as hell wish I would have had a working GPS that weekend. I've always known the glass was slower, but I never would have thought 5mph or even upwards to 8 like Roostwear stated.
Dan, in terms of boats your size, our old Eliminator bubble deck would run MUCH faster up on top of 6" to 10" chop than it would on flatter water, but it didn't have a diverter or droop to help loosen it up in flatter water, so it had to be run on top of bigger stuff to move out.
Chris

[FILUCKY]

When the water is glass don't look at your speed it will wreck a perfectly nice day.

[HotDogz]

I can pick up 2-3 mph in light chop, couldn't figure out why for the longest. With a little investigating, it seems I am a victim of hook and rocker. My guess would be that w/chop I can air out a little taking some of the hook effect, but with a glass lake there is no lift assist allowing the full effect of my hook to become apparent. :(
With chop I might make 68-67, without 65-66mph. Going into the wind seems to help also. More learning, more work.

[Danhercules]

This is making me feel a lot better. I do not have a good solid number yet. I was with Victorfb at Elsinore and we did 69 (sorry vic! :D ) I had full tanks. The boat did not feel as fast as it did the weekend before. I cannot wait till the 4th and get some good water below Avi and above Needels. It was nice riding on the glass though.

[LVjetboy]

"5-10 mph depending on water."
Since this...
http://members.cox.net/lvjetboy/HowFast.jpg
was on glass, I guess my real top speed's 110 mph. Cool. That makes me faster than bp. :D
"What do you think would be faster...Running on glass into the wind or running on 6" chop with no wind?"
Trick question. Where's glass with wind?
jer

[shootingstar72683]

My Cheyenne runs faster going into the wind, especially when carrying extra weight. I took a big guy for a ride once and could only run 85 downwind but the return trip we hit 95. My 26' Firehawk is the same way, wind helps lift which helps speed. gotta watch it tho, it could cause a blowover. :D
I'll take a ride if you're giving them away. Need the rush!!!!! Have fun on the run.

[Wicked Performance Boats]

If you want your boat to go the fastest. Take out the babes and the buddies, the anchor and the toolbag,and the cooler, leave 2or3 gallons of gas in the boat and wait for 4to6 inches of chop. Then make 1 pass with a GPS. Now you have bragging rights. Now go back to beach an fill your boat with gas and all the neccessary stuff[babes, buddies, cooler and tools,] and go have fun! Budlight :coffeycup

[Wicked Performance Boats]

This is making me feel a lot better. I do not have a good solid number yet. I was with Victorfb at Elsinore and we did 69 (sorry vic! :D ) I had full tanks. The boat did not feel as fast as it did the weekend before. I cannot wait till the 4th and get some good water below Avi and above Needels. It was nice riding on the glass though.
Hurk, Needles is spelled" N_E_E_D_L_E_S! [Just busting your balls] lose some weight if you want to go faster, I'm trying Budlight

[TRG]

my boat feels quite squirly in the wind (with a little chop) dont care to take her out when the wind is howling, but in glass ide have to say that it does perform much better where as i dont stand on it (anymore) in uncertain water!
Nice topic BTW!
Todd

[Danhercules]

Hurk, Needles is spelled" N_E_E_D_L_E_S! [Just busting your balls] lose some weight if you want to go faster, I'm trying Budlight
I did lose some. But I found it agian. I guess I had me a tipe-o. LOL :rollside:

[bp]

"5-10 mph depending on water."
Since this...
http://members.cox.net/lvjetboy/HowFast.jpg
was on glass, I guess my real top speed's 110 mph. Cool. That makes me faster than bp. :D
"What do you think would be faster...Running on glass into the wind or running on 6" chop with no wind?"
Trick question. Where's glass with wind?
jer
hey jer, anytime you wanna line up, just bring it on over :D :D :D
stereo, no stereo, tunes, no tunes.. however ya want it.
i DO have a timeslip that says 109, and that was last year when it was slow :D .
chop vs glass is a slight bit different, but i really don't see any changes in et/speed between the two, unless the wind is from the head or from the rear. if i'm running into, say, a 5-10mph headwind, i can pick up between .04 to .10 in et, and maybe 1 or 2 mph, like from 104 to 105. if the wind is real strong from the rear, it will have the reverse effect on my boat. so, conditions will result in changes in et/speed, but not so much as it would terribly noticable on river, like a 5% change, or something like that. top speed of the boat can be easily changed through setup/hardware changes, once you know how/what hardware effects your boat.

[pops1]

All right, my boat is not a hot rod as top end with two people in the boat is 55mph. I took the boat out the other evening just before dark and the water was glass. The ride was fantastic, but the best I could do was 46mph.
RPM was the same (4200) and it didn't matter where the diverter was.
I guess I've never really paid attention before when the water was smooth because I usually have the wife and kids in the boat and won't do hard runs. Is a 10mph scrub of top speed common in very smooth water? The boat felt heavy as hell.
Bad, its like glue on wetted surfaces.