Future of pods

Sucking any kind of floating debris directly into the props for starters, is my beef with them. With rear facing props, most floating debris will get deflected by the drive itself. Another poster mentioned that you cannot do more than 40 knots with foward facing props.

Forward facing or aft facing makes no difference in a hard grounding or say hitting a dead head. Either way your going to have propeller and or housing damage. That being said, Forward facing or Tractor drive systems have been proven superior in all but a few slim categories. Better maneuvering, fuel consumption, cavitation by pulling in undisturbed water etc. Funny fact NEO is that Steerprop and Schottel have forward facing systems that are ice classed to ABS A-5 and IACS PC-1 / the most stringent ice classification there is.
Polar ice breakers use variable pitch tractor drives to mill ice and blow ice ridges by vectoring. Not here to say that Volvo penta's machine is going to be eating polar ice but you don't have any other concerns with a tractor drive from a conventional set up other than wrapping your head around it. Repeat after me, It's all in my head, it's all in my head...

I don't know if that is true. I was delivering a 64' Hatteras MY from the Bahamas to St. Thomas. There was a Meridian doing the same leg as us and he hit a dead head at 8 knots with Zues. It sheered 2 of the mounting bolts and bent the other 2 but was still hanging onto the boat. He made it about 60 miles that way on one engine, when he pulled into St. Thomas they removed the drive and it had no damage to the drive or the props, they installed new bolts and were on their way again. I would think foward facing props would've been mangled in that situation.

I also saw a Searay come into Hillsboro inlet over the bar that looks like the opening to the inlet on the north side. The entire boat skidded over the beach/sand bar, left the drives on the sandbar and then the boat landed into the lagoon. Again the drives were not in bad shape, nor the props and sheered the bolts like they're supposed to.

From personal experience I would think foward facing propellors would be more apt to wrap crab trap line around them and suck debris into them at least at slower speeds than aft facing. From my experience with outboards and stern drives (both aft facing obviously and with similar lower unit shapes) crab trap lines and other things will hit the front of the lower unit and be deflected a lot of time by the lower unit before they get into the propellors. I do prefer the use of bronze propellors on the volvo over s/s on the zues for the fact that you can get antifouling to stick a little better on them (propspeed) and you can't on s/s. Perhaps I am wrong, but I would prefer aft facing.

My understanding is the Zeus and IPS drives have self sealing bellows if the drive is sheared off? Is this correct? I mentioned previously that my experience with these two units is very limited and I don't know how robust these two systems are. I do have a great deal of time dealing with the bigger machines and can attest to the bullet proof nature of those systems but of course they're different animals all together with individual prop blades to be replaced on the shaft if damaged etc. It makes sense though in the pleasure boating market, The more parts that you can sell from damaged or worn out systems the better. Kinda like razor blades, We all know that Gillette can produce a blade that would last a year but then they wouldn't be in business very long. As time goes by I'm sure Volvo and Merc will refine their systems to be better , faster and stronger as the market dictates. (Hopefully)

Yes, they have bellows and are designed to sheer off without any water intrusion into the boat. The drives have a splined shaft and it goes into the thru-hull section with 4 bolts that sheer off in the case of an impact. The drives general fare pretty well on most groundings and just fall off instead of destroying themselves. It's almost like how a stern drive goes into the gimble plate.

Triple and quads?? Pods have reduced the overall space envelope of engine rooms.
Designers & builders love this as they can take a frame or two out of the machinery space and enlarge the S/R or heads and up sell the interior of a 80 footer by saying that it has the volume of a hundred footer. I did get aboard the Lazzara sport a couple of years ago that had quads and was appalled at the lack of space for maintenance. You really had to work to pull a dip stick and good luck if you had to change out a starter motor. I'm all for innovation but the builders and engine manufacturers have to be realistic about access to critical components on the sides of the engines. The way some of these multiple installations are set up it' a sure recipe for rusted and abused iron after a year or two from lack of maint.

Captains I've spoken to have no issues operating the boat with either the palm beach controls or the joystick, you can use either or, and with zues you can go immediately from one control to the other control without having to access anything. IPS you have to press an access button for 2 seconds.

As for the other issue including on the searays......most owners and Captains simply don't want to have to maintain 3 or 4 engines and find it to be a larger expense AND hassle......even for your simple pre-voyage checks.....think about it, 4 engine oils, 4 coolant levels, 4 gears oils, 4 belts, etc etc..... The problem I have is once you get more than 2 pods you start losing fuel economy. On twin pods you get 30-40% fuel economy savings over traditional, 3 pods it drops to 15-20% (still somewhat worthwhile) on a quad installation 5-8% economy which is not even worth it to have to deal with maintaining 4 engines.

For the most part they have in a lot of boat types. When was the last time you saw a stern drive center console? Or fishing walkaround. I think there are some segments where stern drives will always be the leader, such as race boats.

My opinions pretty much follow Olderboater's. I think if they can come up with big pods so that 60-100' yachts can use them in a twin engine installation and they can handle 1500-2600HP (think Cat/MTU) that you will see them take hold and a lot of builders use them. There are lots of upsides such as better fuel economy, less vibration, maneuverability, etc. Also, if you have an issue with a pod, you could technically change it in a few hours with a diver and be right back in business.