How much could salt effect the size of my wake?

In theory wouldnt a boat with the same weight have a smaller wake in salt due to things being more bouyant in salt? I was just looking at pics from the test drive of my boat on a lake, to some recent pics in Key Bescane Bay. Any thoughts?

That's correct. You would have to weight a boat down more in salt water to get the same wake you would have in fresh water. I dont have a whole lot of experience riding in salt water, though, so Im not sure how much more weight you would add.

I would say 10-20 percent more to achieve the same wake.

The specific gravity of ocean salt water generally ranges from 1.02 to 1.025. That means saltwater is 2% to 2.5% more bouyant.

Thus, you need 2.0 - 2.5% more weight to counteract the exta bouyancy. In a boat that normally weighs 5,300# (3500# boat, 1500# ballast, 300# of people & gear), you'd only need an extra 106 to 135 pounds of ballast. Find one more small rider/passenger and you're set.

Although your theory makes sense, It doesn't hold true in our salt water. You need more than that.

The actual SG figures for the Pacific Ocean range from 1.023 to 1.025 (@60 degrees F, to be exact). Assuming fresh water weighs 8.34 lbs/gal and 1 cu. ft = 7.48 gals, a 5300# boat displaces 2.11 fewer cubic feet of sea water compared to fresh water.

2.11 cu. ft. of sea water weighs 134.9 pounds. Thus, if you add 135# to the boat, it will displace the same volume of sea water as it did in fresh water.

I took physics a long time ago, and I could have forgotten something. Assuming we're not talking about boarding in the Salton Sea, why are adjustments necessary for the salt water you ride in?

we have had this discussion before fellas, but I have to agree that Jeff G is correct.
The difference in bouancy in salt is only 1/4" per 12" of depth.
If your boat only drafts 22" (like my X-10) then she would sit (about) 1/2" higher in saltwater then she would in fresh water. The concensis on the last thread (many months ago) was that if you could tell the difference between your boats wake in salt vs. fresh, "with all other things being equal", then you are some type of genius!

I have rode both and primarily ride in saltwater, I have people tell me the wake is fantastic on my boat, only that their eyes sting every time they get sprayed in the face!!!

my $.02 for the day!

Salt water should have a higher viscosity and a different surface tension (not sure which way).

Both of these could affect planing (lift of boat and rider at speed)???

how much more does it hurt to fall in salt water since it is more dense?

leo - I think this thread made my head hurt a lot more than catching my edge in salt, or fresh water.

Jeff - thanks for that.

Jeff, I actually agree with you but from our experience, it sems you need to add more tweight than that to get a comparable wake. It sould be due to other factors though. The fact that it's easier to edge in fresh water could also have something to do with it.

i think it pops harder than fresh water so maybe you don't need as big of a wake. I also find that the landings are harder. but maybe that one day i was riding i was just off.

Launches and landings in sea water probably are harder because the water is both more viscous and more dense. And in looking up info on this, I confirmed what I always have "felt" -- faceplants in cold water (fresh or sea) probably do hurt more because the water is more viscous (and slightly more dense).

Brian, I've tried to go a step farther and see if sea water has different hydrodynamic properties that could require more ballast. So far, I've confirmed that it does have different characteristics, but I've about given up trying to figure out whether/how this might alter a wake.

At any rate, you and I really are not that far off. You suggested 10-20% more ballast, and my figure of 135# is nearly 10% of the ballast I started with (1500#).

Although it may be inperceptible on something as small as a wake, freshwater will create waves with a more vertical face than salt water. Also, the period of waves in freshwater is closer together.

I was just thinking about it if salt water is more dense then the ballast will weigh more filled with salt rather then fresh, so the size is probably the same, i was probably just so pumped up that i was getting a new boat it looked huuugeee.