Inflatable Dinghy Speed
 

Am looking for ways to get a bit more speed out of my inflatable dink.
There's no noticeable increase in boat speed past 1/2 throttle, although the
RPMs seem to increase and the bow lifts somewhat.

It's an 8'6" West Marine (Zodiac) rollup with stiffening slats -- so is flat
bottomed. Power is Nissan 3.5HP -- same as Tohatsu 3.5 and Mercury 3.3 I'm
told.

I've removed the tilt pin because that seems to give the best performance.
In the pin's lowest position the bow lifts excessively. I'm not sure at what
height the anti-cavitation plate should be, but it doesn't seem like much
adjustment is possible. As far as I know there's only one prop (diameter &
pitch) available for this outboard.

Would appreciate any suggestions.

Len

-- Eliminate "ns" for email address.

Inflatable Dinghy Speed
 

On Sun, 19 Oct 2003 00:22:27 GMT, "Len Krauss"
wrote:

Am looking for ways to get a bit more speed out of my inflatable dink.
There's no noticeable increase in boat speed past 1/2 throttle, although the
RPMs seem to increase and the bow lifts somewhat.

It's an 8'6" West Marine (Zodiac) rollup with stiffening slats -- so is flat
bottomed. Power is Nissan 3.5HP -- same as Tohatsu 3.5 and Mercury 3.3 I'm
told.

I've removed the tilt pin because that seems to give the best performance.
In the pin's lowest position the bow lifts excessively. I'm not sure at what
height the anti-cavitation plate should be, but it doesn't seem like much
adjustment is possible. As far as I know there's only one prop (diameter &
pitch) available for this outboard.

Would appreciate any suggestions.

You won't get much more speed out of it no matter what you do. At 1/2
throttle you're probably already going as fast as you can go without
planing, and even increasing the throttle all the way you're not gonna
get that setup to plane except in maybe the very best of calm flat
conditions with one very light person onboard.

All I can suggest is move some weight forward to keep the bow down.
This will increase the LWL and get you going just a little faster.

The anti-cavitation plate should be maybe in inch or two below the
transom bottom. But it doesn't really matter and you probably won't
notice much difference wherever it is... as long as the prop is in the
water.:)

Steve

Inflatable Dinghy Speed
 

You are not going to get any more feed unless you can get it up on plane
and rollups are incredibly hard to get planing. Try sitting further
forward. Get a piece of PVC pipe about 2' long that will slip over the
tiller and clamp it in place. That seems to be a popular solution but
don't expect miracles.

Len Krauss wrote:
Am looking for ways to get a bit more speed out of my inflatable dink.
There's no noticeable increase in boat speed past 1/2 throttle, although the
RPMs seem to increase and the bow lifts somewhat.

It's an 8'6" West Marine (Zodiac) rollup with stiffening slats -- so is flat
bottomed. Power is Nissan 3.5HP -- same as Tohatsu 3.5 and Mercury 3.3 I'm
told.

I've removed the tilt pin because that seems to give the best performance.
In the pin's lowest position the bow lifts excessively. I'm not sure at what
height the anti-cavitation plate should be, but it doesn't seem like much
adjustment is possible. As far as I know there's only one prop (diameter &
pitch) available for this outboard.

Would appreciate any suggestions.

Len

-- Eliminate "ns" for email address.




--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Inflatable Dinghy Speed
 

Usually takes 8hp or even 9.9 to get an inflatable up on a plane with any real
load. But then what's the hurry? The 3.5 is nice and small. Take it slow and
row once in a while.

RB

Inflatable Dinghy Speed
 

I agree. Why would anyone in a "hurry" ever buy a boat in the first
place??



On 19 Oct 2003 11:22:38 GMT, (Bobsprit) wrote:

Usually takes 8hp or even 9.9 to get an inflatable up on a plane with any real
load. But then what's the hurry? The 3.5 is nice and small. Take it slow and
row once in a while.

RB


Larry W4CSC

US Supports Apartheid! Vetoes UN resolution
condemning Apartheid Wall.
http://www.antiwar.com/hacohen/h052103.html
http://www.theage.com.au/articles/20...917478560.html
Can apartheid at home be far away?....
Apartheid NOW! Wall off Mississippi!

Inflatable Dinghy Speed
 

On Sun, 19 Oct 2003 11:22:38 +0000, Bobsprit wrote:

Usually takes 8hp or even 9.9 to get an inflatable up on a plane with any real
load. But then what's the hurry? The 3.5 is nice and small. Take it slow and
row once in a while.

RB
I had a similar situation: A BRIG 9ft inflatable with rigid flooring,
inflatable keel. I was able to get it up on plane with one person only
using 5HP. I upgraded to a 8HP Nissan to make it plane with two people
and some luggage.

Dirk

Inflatable Dinghy Speed
 

Why? Well, I've had to anchor miles away from the dock and I don't want to
take forever to get there. I've had incredibly strong currents against me
and like going forward. When I go diving I have at least 1 other person in
the dinghy and at least 2 sets of dive gear and it can be miles to the
dives sites. I upgraded from a 9.8 Nissan to a 15 Yamaha and have been
very happy ever since. Oh, it also pulls boats off of sandbars quite well!

I don't know if you've ever anchored or moored off of Key West, but the
city mooring field is probably 1.5 miles from the main docks. There's a
cut between Garrison bight and the main town and the water RIPS through
there. With a small motor you'd never make it against full flood.

I guess that I'm just kind of person who likes to get things done in a
timely manner. I also spend 8 months of the year using my dinghy as my
mode of transport from the boat, so this isn't just a weekend getaway thing
where I'm trying to unwind.

-- Geoff

(Larry W4CSC) wrote in
:

I agree. Why would anyone in a "hurry" ever buy a boat in the first
place??



On 19 Oct 2003 11:22:38 GMT, (Bobsprit) wrote:

Usually takes 8hp or even 9.9 to get an inflatable up on a plane with
any real load. But then what's the hurry? The 3.5 is nice and small.
Take it slow and row once in a while.

RB

Inflatable Dinghy Speed
 

Geoff -- You are so right. Been there and done all those things, including
getting to and from the KW mooring field. As you may have surmised, I'm
trying to avoid the added weight of a serious dink and outboard. My dink's
rated for 4HP. I think I could probably go to 5HP, but it seems that won't
do much better.
Len

Why? Well, I've had to anchor miles away from the dock and I don't want
to
take forever to get there. I've had incredibly strong currents against me
and like going forward. When I go diving I have at least 1 other person
in
the dinghy and at least 2 sets of dive gear and it can be miles to the
dives sites. I upgraded from a 9.8 Nissan to a 15 Yamaha and have been
very happy ever since. Oh, it also pulls boats off of sandbars quite
well!

I don't know if you've ever anchored or moored off of Key West, but the
city mooring field is probably 1.5 miles from the main docks. There's a
cut between Garrison bight and the main town and the water RIPS through
there. With a small motor you'd never make it against full flood.

I guess that I'm just kind of person who likes to get things done in a
timely manner. I also spend 8 months of the year using my dinghy as my
mode of transport from the boat, so this isn't just a weekend getaway
thing
where I'm trying to unwind.

-- Geoff

(Larry W4CSC) wrote in
:

I agree. Why would anyone in a "hurry" ever buy a boat in the first
place??



On 19 Oct 2003 11:22:38 GMT, (Bobsprit) wrote:

Usually takes 8hp or even 9.9 to get an inflatable up on a plane with
any real load. But then what's the hurry? The 3.5 is nice and small.
Take it slow and row once in a while.

RB

Inflatable Dinghy Speed
 

Len Krauss wrote:

Geoff -- You are so right. Been there and done all those things, including
getting to and from the KW mooring field. As you may have surmised, I'm
trying to avoid the added weight of a serious dink and outboard. My dink's
rated for 4HP. I think I could probably go to 5HP, but it seems that won't
do much better.
Len


I think it's time for a faster dink, probably a light hard dink. Our
PortaBote will do 12-15 knots with the 4 HP. I wouldn't be surprised if
a narrow dory or canoe would really get you in and out about as quickly.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Inflatable Dinghy Speed
 

x-no-archive:yes "Geoffrey W. Schultz"
wrote:

Why? Well, I've had to anchor miles away from the dock and I don't want to
take forever to get there. I've had incredibly strong currents against me
and like going forward. When I go diving I have at least 1 other person in
the dinghy and at least 2 sets of dive gear and it can be miles to the
dives sites. I upgraded from a 9.8 Nissan to a 15 Yamaha and have been
very happy ever since. Oh, it also pulls boats off of sandbars quite well!

I don't know if you've ever anchored or moored off of Key West, but the
city mooring field is probably 1.5 miles from the main docks. There's a
cut between Garrison bight and the main town and the water RIPS through
there. With a small motor you'd never make it against full flood.

That's a slight exaggeration, but basically true. WIth either of our
dinghys (Nissan inflatable or portabote) and the old Evenrude 3.5 hp
motor it takes us about 20 minutes. Of course in the other direction
you go correspondingly faster - hardly need a motor.

We'd have used the bigger Johnson motor that came with the big boat,
but it would never work.

I guess that I'm just kind of person who likes to get things done in a
timely manner. I also spend 8 months of the year using my dinghy as my
mode of transport from the boat, so this isn't just a weekend getaway thing
where I'm trying to unwind.

-- Geoff

(Larry W4CSC) wrote in
:

I agree. Why would anyone in a "hurry" ever buy a boat in the first
place??



On 19 Oct 2003 11:22:38 GMT, (Bobsprit) wrote:

Usually takes 8hp or even 9.9 to get an inflatable up on a plane with
any real load. But then what's the hurry? The 3.5 is nice and small.
Take it slow and row once in a while.

RB


grandma Rosalie