First, I'd like to thank all the responders. You've touched on all the
points I've been pondering.

I think the general trend of the collective wisdom is that, with the
figures I supplied, I can possibly see some gains in efficiency but I am
pretty close to the boat/motor combination being at a point where gains
won't be significant.

Rather then try to reply to each post individually let me see if I can
cover them with this post.

Trim tabs - I'd dearly love them if only to get rid of the starboard
list when I am in the boat alone, which is most of the time. However if
afraid they won't make this years budget.

Four bladed prop - An idea I am playing with but, with the figures given
and keeping the same diameter and pitch, what will that do to top end
speed and RPM?

Lower planning speed - This is the tricky one for me so let me know
where I am going wrong. My boat has a planing hull as opposed to a
displacement hull. It is designed to work most efficiently up on a plane
rather then pushing the water out of the way al la displacement hull.
The
boat falls off the plane and starts pushing water below 20 MPH/4700 RPM.
A lower planing speed may mean it takes longer to get to a fishing spot
but if that means one or two more trips a month in the gas budget I can
live with it. So, and this is where I can see I may be looking at things
wrong, a lower planing speed means lower RPM s with the boat still
operating efficiently, planning rather then displacing, and lower RPM's
mean better mileage.

Whale tail or similar - A budgetable item I have been playing with the
idea of. The things I've read on these additions have all been
advertisements giving glowing reports on them. However, life being what
it is, you can't pay Peter with out stealing from Paul. What is the down
side to be considered?

Thanks again all
Mike


--
MikeG
Heirloom Woods
www.heirloom-woods.net

On Mon, 20 Dec 2004 10:42:42 -0500, MikeG
wrote:

~~ snippage ~~

Lower planning speed - This is the tricky one for me so let me know
where I am going wrong. My boat has a planing hull as opposed to a
displacement hull. It is designed to work most efficiently up on a plane
rather then pushing the water out of the way al la displacement hull.
The
boat falls off the plane and starts pushing water below 20 MPH/4700 RPM.
A lower planing speed may mean it takes longer to get to a fishing spot
but if that means one or two more trips a month in the gas budget I can
live with it. So, and this is where I can see I may be looking at things
wrong, a lower planing speed means lower RPM s with the boat still
operating efficiently, planning rather then displacing, and lower RPM's
mean better mileage.

I think you are way over estimating the difference 3 mph will make on
fuel consumption. Even after several long runs, I doubt if you are
going to save a significant amount of fuel savings such that you will
be able to make additional trips to the fishing grounds. What's the
difference between 17 and 20 in terms of RPM - a 5/600 at the most?
Not enough to justify tinkering with planing speeds.

My Ranger is 20 foot, has a FICHT (which I admit is probably more
efficient than EFI or a carbureted engine), but still, the difference
between 1800 and 2300 is pretty insignificant. I don't have the
figures right at hand, but as I remember, the difference was in the
very low tenths in terms of GPH.

Now having said that, I normally run at 30 mph which is right under 4k
- there I can see savings over the max speed of 42/43 mph at 5500.
But again, the difference is in tenths - closer to a full GPH, but
still tenths.

I'll look for the data when I return from fishing this afternoon and
give you some examples.

Whale tail or similar - A budgetable item I have been playing with the
idea of. The things I've read on these additions have all been
advertisements giving glowing reports on them. However, life being what
it is, you can't pay Peter with out stealing from Paul. What is the down
side to be considered?

For my money, these things suck.

The main reason is that they work even when you don't want them to
work. And you lose the ability to close trim the motor at speed.

On my Princecraft with the Johnson 25, yeah - they make a difference
in a lightly loaded boat by keeping the bow down.

For your application, it wouldn't be something that I would consider.

Later,

Tom

I haven't been following this thread, but you can add SmartTabs for below
$200.00 ..maybe even below $150.00 depending on size ( buy the "scratch and
dent" specials directly from the manufacturer, Nauticus ).

I have them on two smaller boats. They DO keep you on plane longer and at
lower speeds and they DO get you up on plane faster. I surely didn't buy
them for cost (fuel) savings but rather to get up and out from the shallows.
The over-all effects of Trim Tabs ( any brand of trim tabs ) is so very
positive that I think every boatowner/manufacturer ought to consider adding
them. --
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners
..

On Mon, 20 Dec 2004 20:42:10 GMT, "RichG"
wrote:

I haven't been following this thread, but you can add SmartTabs for below
$200.00 ..maybe even below $150.00 depending on size ( buy the "scratch and
dent" specials directly from the manufacturer, Nauticus ).

I have them on two smaller boats. They DO keep you on plane longer and at
lower speeds and they DO get you up on plane faster. I surely didn't buy
them for cost (fuel) savings but rather to get up and out from the shallows.
The over-all effects of Trim Tabs ( any brand of trim tabs ) is so very
positive that I think every boatowner/manufacturer ought to consider adding
them. --
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners

I'm curious as to what kind of boat you have to make that claim.

On my Ranger, trim tabs would be useless because of the transom
design. On my Contender, I guarantee you that the trim tabs have
nothing to do with getting on or off plane faster or longer. Lateral
stability at speed yes - planing, no.

Trim tabs aren't the end all for planing problems which is why I asked
what kind of boat you have. They work for some, but not all.

I have a suspicion that Mike's might not be one of those.

Later,

Tom

continued on the Thread entitled "SmartTabs"

--
..

"Short Wave Sportfishing" wrote in message
...
On Mon, 20 Dec 2004 20:42:10 GMT, "RichG"
wrote:

I haven't been following this thread, but you can add SmartTabs for below
$200.00 ..maybe even below $150.00 depending on size ( buy the "scratch
and
dent" specials directly from the manufacturer, Nauticus ).

I have them on two smaller boats. They DO keep you on plane longer and at
lower speeds and they DO get you up on plane faster. I surely didn't buy
them for cost (fuel) savings but rather to get up and out from the
shallows.
The over-all effects of Trim Tabs ( any brand of trim tabs ) is so very
positive that I think every boatowner/manufacturer ought to consider
adding
them. --
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners

I'm curious as to what kind of boat you have to make that claim.

On my Ranger, trim tabs would be useless because of the transom
design. On my Contender, I guarantee you that the trim tabs have
nothing to do with getting on or off plane faster or longer. Lateral
stability at speed yes - planing, no.

Trim tabs aren't the end all for planing problems which is why I asked
what kind of boat you have. They work for some, but not all.

I have a suspicion that Mike's might not be one of those.

Later,

Tom