pod drives

[jspiezio]

I keep reading and hearing about pod drives and how they will solve all our boating problems as well as curing cancer and ending world hunger. I don't buy it. While I believe they are fuel efficient and maneuverable, they seem like they could be a headache in certain situations. I have heard that they shear off in case of grounding or collision. If one of these beauties shears off your boat and is lost, that might be an expensive proposition. Those pods must cost a bundle, and a spare may not always be immediately available. A situation like Irish Wake's might go from a short haul and some repair to a major expense and season ruining event (if you lost that pod).

I am sure that several of you faithful will have far more informed opinions and much more experience than I have. So, I am counting on some solid feed back and some explanations of the pros and cons from you knuckleheads.

By the way, Predator looks great Mike O and Brewster's was busy.

[In Memory of Vicroy]

There is a thread on baotdiesel.com about the IPS pods. My view is the shear off is a red herring....we can whack off our conventional props, struts, shafts & rudders if hit wrong. The real knock on the pods is you have underwater gears running in oil, exactly like an i/o, and there is simply no way to keep the oil in and the salt water out over time. Seals just ain't that good. Outboads and i/os normally don't stay in the water all the time so they survive by not being in all the time...a litle mono fishing line on the prop shaft and the seals are toast. My view is they are a really dumb idea for larger boats....the joystick idea to manuver is a huge laugh....if you can't manuver a twin engine inboard boat, you need a refresher in physics.

UV

[jspiezio]

There is a thread on baotdiesel.com about the IPS pods. My view is the shear off is a red herring....we can whack off our conventional props, struts, shafts & rudders if hit wrong. The real knock on the pods is you have underwater gears running in oil, exactly like an i/o, and there is simply no way to keep the oil in and the salt water out over time. Seals just ain't that good. Outboads and i/os normally don't stay in the water all the time so they survive by not being in all the time...a litle mono fishing line on the prop shaft and the seals are toast. My view is they are a really dumb idea for larger boats....the joystick idea to manuver is a huge laugh....if you can't manuver a twin engine inboard boat, you need a refresher in physics.

UV

Spot on UV. I think this is a case of "over-engineering".

[Harv]

My view is they are a really dumb idea for larger boats....the joystick idea to manuver is a huge laugh....if you can't manuver a twin engine inboard boat, you need a refresher in physics.

UV

They put 4 giant pods on the new Queen Elizabeth II ocean liner.
2 inboard were stationary, 2 outboard did the pivoting, added to that were 3 bow thrusters with closable doors. She cruises at 30 knots. She also has a joystick. I didn't see any rodholders on her though.

[Carl]

Some of my customers tugs have them as well as the Ferry. They really like them as far as maneuveuring, performance and economy. The tug owner said to the issue of reliability, only time will tell.

On recreational boats, you have to admit there is some benefits with the PODS. But like anything new there is bound to be bugs that will need to be worked out, I'll leave it to the companies and those guinea pigs ( excuse me, those customers ) to work out the issues and maybe somewhere down the road there may be a Pod in my future. For now, I'll stick with the tried and proven traditional shaft, strut, rudder with rear facing prop.

I thought I read when the POD stikes something the Pod detaches but cable-ing is supposed to hold the POD from sinking away into the deep blue. In that case you have a POD dangling just below the boats hull, wouldn't that create an issue with the POD and hull in a soft grounding.

[John F.]

The speed and fuel efficiency with pods are pretty impressive, as is the underdeck space that's available because you don't have shafts, rudders, etc. There was a Spencer rigged with pods at the Miami show, and I think Calyber has also rigged a boat with pods. Time will tell....ethanol cured our dependency on foreign oil and cut prices for fuel for the American consumer, right?

[jspiezio]

Anyone ever heard people talking of retrofits? It seems like a lot of effort to me, but I heard "rumors" of some one here on LI looking to refit a bigger Topaz with these things.

[scot]

The sportfishing PODS and the QEII drives have nothing in common except they both rotate. The commercial units are azmuthing thrusters and the vessels are often designed so the unit can be removed for servicing without drydocking. They are also extremely low rpm, non-planning, displacement vessels. Many of the commercial drives are diesel-electric and all have a ship's engineer checking them daily.

As UV mentioned, a better comparision of long term durability is the I/O unit. Basically the PODS are bronze, over-sized I/Os, that can do a 360 degree rotation. The benefits of handling and performance are there, for the wealthy. If you have the coins to have a specialist working on your ride everytime it burps....go ahead and get-ya-some.

The seal IS the weak link. Personally I don't want (or can't afford) an under water drive system that can be trashed by an O-ring that sucked up some mono.

[JP Dalik]

Personally I don't want (or can't afford) an under water drive system that can be trashed by an O-ring that sucked up some mono.

Scot,
That means you don't want and outboard, an I/O or a pod. Good thing your building a straight inboard. Just don't fish any spectra or you might be doing a haul out for the cutlass.

In my opinion they all cost alot of money. As Brewster says if you don't have the money don't play the game. I could buy an awful lot of fish for the money I spend to go fishing. We're all afflicted with the disease. Some choose to bleed more money than others.

The numbers off of the Spencer boat with the Pod drives looked pretty good in the last Marlin Mag. That owner just chose to bleed a little more than I can afford.

You got any more pics of your project.

[scot]

JP,

That means you don't want and outboard, an I/O or a pod.

That's correct, I don't care for any of the above. But for me, it's about what I'm comfortable working on and I have an industrial/marine background. I prefer HD stuff, even when the down side is less speed.

Sorry, no new pics lately, gathering engine stuff. Too hot in Texas for me to grind glass. Fall is getting closer by the day.

[Rawleigh]

Fall is getting closer by the day.

Ain't that the truth!!!

[jspiezio]

Disregarding cost, I'm a little uncomfortable with these things. Maybe after a few years I'll feel differently.

[John Brownlee]

I have run several IPS equipped boats, including the Spencer, and most recently, the 39 SeaVee. While I too have had reservations about their ultimate longevity, there are now quite a few of them on the water and there doesn't seem to be any noticeable problem cropping up with them. Yet, anyway. They are expensive, without a doubt.

I can tell you this; IPS provides the most amazing maneuverability I've ever experienced. Vic, no one can drive a twin-screw inboard like you can drive an IPS boat. They spin like a helicopter rotor, back down at high speed without burying the transom, and you can walk the thing sideways in or out of a slip effortlessly. And when the Sky Anchor feature gets perfected, you will simply push a button and the boat will stay in the exact spot you want it to regardless of wind or tide. No more anchoring over a wreck.

It's amazing technology.

[nic]

back down at high speed without burying the transom,

and where is the fun in that?

Nic

[Tony Meola]

John

I don't know how they are going to hold up in areas that are shallow. Since you don't have to navigate Barnegat Bay you have no worries. I bet one of those on that bay will be high and dry about 50% of the time.

Drawing only 3 feet of water makes me nervous at times.

[Carl]

Tony,
I have always thought of a boat as a comprimise. You figure out what you want it to do and narrow your selection down.

If your going to be doing your boating in Barnaget Bay, a straight shaft / strut design would not be my choice either, unless it was an old Penn Yann Tunnel drive or you had a full keel. Pods would be a bad choice in that application as well, in my opinion anyway. Outbords and I/O's have there place and that is it for me, maybe the only other real good choice is jet drive, but then you don't want sand running thru the pump either.

[AndreF]

Carnival Cruise Lines uses them on their 1000' ships. I watched them churn the mud up leaving Costa Rica and Belise.

[Tony Meola]

Sim

The average depth in Barnegat Bay is probably 6 feet. Unfortunately I have to cross the bay to get outside.

It gets better, years ago we got hung up in the channel in the Forked River during an extreme low tide. While you wouldn't do any damage in the river, you just come to realize you never know when the water is just going to be too low. You go over an area time after time and never a problem then one day you just stop cold. Its just a fact of life on Barnegat Bay.

I would hate to hit that hard sand with the pods. Bad enough you bend a wheel or two on a shaft drive, but on a pod that is probably a foot lower, its going to be a long long ownership trying to cut that bay.

[Carl]

I agree with you Tony, that bay and Pods sound like a match made in hell. We have a friend who has had several large Vikings thru the years that runs out of that bay, his theory is to just run fast so he'll be higher in the water. Sometimes it works...sometimes it don't. When it don't he manages to get her off the bars, most times without issue to the running gear, I can't speak to cutless wear and the issues of ingesting sand and muck into the engines cause he don't keep the boats very long. But if he had pods I think he'd be out of the water a few times a season for new pods

[John Brownlee]

Tony:

I hear you, although we have PLENTY of shallow water here in the Keys. Six feet of water would be considered a luxury at most Keys marinas at low tide. I guess the difference is that it doesn't shift around too much, and the water is clear so you can see it before you hit it.

I'm not saying the IPS tractor drives are perfect, but they sure are impressive when you drive them.

JB

[jspiezio]

I love innovation. But, I wouldn't want o be the guinea pig. I'd love to get a chance to see the actual construction on some of these, and to get some feed back a year or three down the road first.

As far as grounding goes, it sounds like "limping back" might often be out of the question.