Page 1 of 4 1234 LastLast
Results 1 to 10 of 35

Thread: How bad does smooth water cut your top end?

  1. #1
    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.

  2. #2
    Mandelon
    Did ya put in the drain plug?
    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.....

  3. #3
    Senior Member
    Join Date
    Feb 2009
    Location
    Irvine, CA
    Posts
    2,885
    "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

  4. #4
    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.

  5. #5
    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.

  6. #6
    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.

  7. #7
    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

  8. #8
    BrendellaJet
    I think all boats are different. I know mine runs wetter in glass. Give me some mild chop and it gets measureably faster.

  9. #9
    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

  10. #10
    Senior Member
    Join Date
    Apr 2010
    Posts
    2,920
    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

Page 1 of 4 1234 LastLast

Similar Threads

  1. Smooth Bottom..
    By Fired Up in forum Fiber glass & Hull Repair
    Replies: 3
    Last Post: 10-03-2007, 05:19 AM
  2. One smooth looking 27 shadow
    By Strippoker in forum Sandbar
    Replies: 38
    Last Post: 07-30-2007, 05:41 AM
  3. Smooth water close to the DFW area???
    By Cliff98z in forum Boating, Central
    Replies: 13
    Last Post: 08-22-2005, 10:50 AM
  4. How smooth ....
    By Jbb in forum Sandbar
    Replies: 15
    Last Post: 08-04-2005, 08:12 AM
  5. How Smooth?
    By Ziggy in forum Boating, West
    Replies: 14
    Last Post: 11-13-2003, 05:28 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •