The new boat I'm thinking of buying is a deep vee. At the bottom of the
vee, as it were, is a small flat "pad." The pad serves several functions
which I won't get into here.

Thus, if you look at the stern of the boat from outside the hull, you
see a shape sort of like this:

\_/

The pad is about three inches wide. On the inside of the boat, a piece
of marine ply is epoxied to the fiberglass hull, and then the ply is
fiberglassed. Attached to the fiberglass is the bilge pump and its float.

There is room right there to drill through the hull bottom and install
a straight shooting down fishfinder/depthfinder/temp gauge transducer.
We'd make the ply circle hole a bit larger than the transducer and then
epoxy the ply edges, just for insurance.

The question is this: would a through hull like this be "mo' betta'"
than the usual stern mount transducer in terms of accuracy? There are
several transducers available that barely protrude from the bottom, so I
am not worried about interfering with the stream of water hitting the
engine's lower unit under water. Do through hull transducers tend to
fail at a higher rate than transom mounts? Are there other
considerations I should ponder?

Price is not an issue: there's really not much difference in pricing
between a good transom mount and the through hull.

Thanks.

On Wed, 04 Jul 2007 18:22:49 -0400, HK wrote:

Price is not an issue: there's really not much difference in pricing
between a good transom mount and the through hull.

As long as the transducer makes contact with clean water, there is no
difference between the two systems. The key is to keep the transducer
in the water flow and not where air and foam can interrupt the sonar
signal.

It's really a matter of appearance.

Short Wave Sportfishing wrote:
On Wed, 04 Jul 2007 18:22:49 -0400, HK wrote:

Price is not an issue: there's really not much difference in pricing
between a good transom mount and the through hull.

As long as the transducer makes contact with clean water, there is no
difference between the two systems. The key is to keep the transducer
in the water flow and not where air and foam can interrupt the sonar
signal.

It's really a matter of appearance.


Ahh. Good. I'm leaning towards the through hull, to avoid wires on the
transom.

Short Wave Sportfishing wrote:
On Wed, 04 Jul 2007 18:22:49 -0400, HK wrote:

Price is not an issue: there's really not much difference in pricing
between a good transom mount and the through hull.

As long as the transducer makes contact with clean water, there is no
difference between the two systems. The key is to keep the transducer
in the water flow and not where air and foam can interrupt the sonar
signal.

It's really a matter of appearance.

I have heard that it is tougher to get clean water with a transom mount.
I have always just shot thru the glass, because it is only a depth
finder, and not a fish finder, I have never had a problem. The first
time I did this, my marina told me they shot fish finders thru the hull,
and as long as there are not voids in the fiberglass (ie solid glass)
they never have problems shooting thru the glass.

On Thu, 05 Jul 2007 10:28:55 -0400, "Reginald P. Smithers III"
wrote:

Short Wave Sportfishing wrote:
On Wed, 04 Jul 2007 18:22:49 -0400, HK wrote:

Price is not an issue: there's really not much difference in pricing
between a good transom mount and the through hull.

As long as the transducer makes contact with clean water, there is no
difference between the two systems. The key is to keep the transducer
in the water flow and not where air and foam can interrupt the sonar
signal.

It's really a matter of appearance.

I have heard that it is tougher to get clean water with a transom mount.
I have always just shot thru the glass, because it is only a depth
finder, and not a fish finder, I have never had a problem. The first
time I did this, my marina told me they shot fish finders thru the hull,
and as long as there are not voids in the fiberglass (ie solid glass)
they never have problems shooting thru the glass.

My Ranger has a very odd transom and I don't have a problem with clean
water - even in turns. It's all in how you set it up.

Through glass is never going to be as sensitive and, although it's not
happened to me, can distort the returning echo giving a false depth
reading. Note that it's never happened to me.

Short Wave Sportfishing wrote:

Short Wave Sportfishing wrote:
On Wed, 04 Jul 2007 18:22:49 -0400, HK wrote:

Price is not an issue: there's really not much difference in pricing
between a good transom mount and the through hull.
As long as the transducer makes contact with clean water, there is no
difference between the two systems. The key is to keep the transducer
in the water flow and not where air and foam can interrupt the sonar
signal.

It's really a matter of appearance.

My Ranger has a very odd transom and I don't have a problem with clean
water - even in turns. It's all in how you set it up.

Through glass is never going to be as sensitive and, although it's not
happened to me, can distort the returning echo giving a false depth
reading. Note that it's never happened to me.


I've never had problems with transom mount transducers, but this time on
the boat we're considering, there is an easy way to mount a
through-hull, with easy access to where it should be mounted. This sort
of mounting will keep a wire off the transom, and will prevent the
transducer from being whapped by the trailer bunk if I load the boat up
catawampous, as it were.

On Thu, 05 Jul 2007 10:54:37 -0400, HK wrote:

Short Wave Sportfishing wrote:

Short Wave Sportfishing wrote:
On Wed, 04 Jul 2007 18:22:49 -0400, HK wrote:

Price is not an issue: there's really not much difference in pricing
between a good transom mount and the through hull.
As long as the transducer makes contact with clean water, there is no
difference between the two systems. The key is to keep the transducer
in the water flow and not where air and foam can interrupt the sonar
signal.

It's really a matter of appearance.

My Ranger has a very odd transom and I don't have a problem with clean
water - even in turns. It's all in how you set it up.

Through glass is never going to be as sensitive and, although it's not
happened to me, can distort the returning echo giving a false depth
reading. Note that it's never happened to me.


I've never had problems with transom mount transducers, but this time on
the boat we're considering, there is an easy way to mount a
through-hull, with easy access to where it should be mounted. This sort
of mounting will keep a wire off the transom, and will prevent the
transducer from being whapped by the trailer bunk if I load the boat up
catawampous, as it were.

If you don't mind me asking, what brand/model of boat are you thinking
about?

HK wrote:
I've never had problems with transom mount transducers, but this time on
the boat we're considering, there is an easy way to mount a
through-hull, with easy access to where it should be mounted. This sort
of mounting will keep a wire off the transom, and will prevent the
transducer from being whapped by the trailer bunk if I load the boat up
catawampous, as it were.


I currently have a shoot thru and I'm not impressed with the performance
of the sonar. It could be my installation, but it appears to be by the
book. I tend to lose readings or get inconsistent result when in shallow
water. And in SW Florida, we have ALOT of that.

I've been debating the same thing you are currently discussing. We have
a sort of step in the hull at the transom, plus trim tabs, and it
appears to me the thru-hull the better option. With the unit we have,
while mounted ahead of the step, should always be in clean water.

Looking at the various options for the manufacturer we have, the
low-profile thru-hulls do not include temp, which is something I want to
add if I am going to go thru the process of drilling hold in my hull. I
am hesitant at the one which include temp, but at a cost of an
additional wedge/block extending below the hull line.

On Thu, 05 Jul 2007 10:28:55 -0400, "Reginald P. Smithers III"
wrote:

I have heard that it is tougher to get clean water with a transom mount.
I have always just shot thru the glass, because it is only a depth
finder, and not a fish finder, I have never had a problem.

I'm shooting through the glass on my trawler with good results,
typically on soundings up to 1500 feet of water, and one less hole in
the boat.

HK wrote:
Are there other considerations I should ponder?

These days, I assume my boat will outlast its electronics so I try to
avoid major surgery or permanent type mountings if I can. In fact, I
have an old through hull transducer, no longer in use, that I'll have
to remove at some point, leaving a rather large hole to repair.

Just a thought.

Rick