Are IPS hulls shallower V than shaftdrive?

[Nautical]

I guess we could argue these points from now till eternity, some have a very fixed idea about new technology, IPS / pods, sports cruisers, flybridge, electronics etc etc. In the meantime the market will dictate what is acceptable and what are the demands/needs of the boating public in the 21st century and react accordingly. To date I haven't seen any market in any industry be dictated to by one or two manufacturers (except Microsoft perhaps) to the point the consumer was bludgeoned into buying their product exclusively, the market generally sorts itself out. If Pods etc are a success then that is what the market wanted. Whether it detracts from some element of old school fun / enjoyment really isn't the point, people will always gravitate to product that makes life easier, more enjoyable and if it gives you the ability to look the doofers without the trauma and tears then that is a bonus.

I think on here we get very polarised in our views even perhaps dare I say it, "a little insular" without factoring in that the vast majority of boaters never get into this sort of detail and discussion. Most want happy days, enjoyment, a bit of a thrill going solo and getting away from it all with family and friends. I would hazard a guess that the majority too are really not into the mechanical side either, if it breaks they get a man to fix it, sure the basics but when it comes to changing belts, tinkering with timing, pulling bits off the engine they are out of their depth and best leave well alone. I would comment though if your joystick gives up the ghost you can just centre the pods with the special key tool and drive home ala conventional shaft drive, much as if you would if you had hydraulic failure with your rudders.

In the end like most things it will be a matter of mix and match, IPS will not die only increase but neither will shaft drive or OD they have their place and will continue to do so. IPS has brought a bold new world to boating and I would not be shy in saying so sold more boats than may have been sold previously certainly moved customers into bigger and more expensive models that they would not have considered before.

Finally , I don't really get why some quarters believe that sea manship can be attributed to what drive system your boat has. I ve seen long time boaters act like total idiots and newbie IPS owners cautious, diligent and responsible.

Unless of course a shaft drive flybridge can exert some magical ether over human behaviour ;-) !

 

[Nick_H]

But a newbie boat owner with IPS wont care that boats used to have shafts, and were driven differently, any more than a newbie car driver will care that cars have always had steering wheels. They will learn to use the steering system installed on their chosen vehicle, regardless of whether its new technology or not. Either way, I don't see they need to know how it works, just that it does.

 

[oceanfroggie]

Fair comments Trevor. As I said, personally, the jury is still out on what looks like a bold new technology, and as you say time will tell and the market will sell what sells.

The skill issue is not really an IPS issue per say, rather that more newcomers to boating are starting with 35-45ft boats, but used to get some reasonable training in boat handling. IPS simply makes it easier to skip or minimise what was a normal "tool up process" for new owners, hence the potential skills deficit when using wheel and throttle levels. Training is about the right attitude, and some who don't bother with handling skills may also be likely to skimp on weather, navigation and safety skills.

 

[MapisM]

[ QUOTE ]
Mapis, another point.
...
Worse still, the sine of 20degress is .34. Blimey! So in a tight turn, you'll have a couple of hundred kgf horizonatal force in a shaft+rudder boat to turn the hull on the sea, and in an IPS boat you have in addtion 68% of that force multiplied by the distance from drive to roll centre (say 1-1.3m) acting as a twisting torque banking the boat harder into the turn. Blimey!

[/ QUOTE ]Hmm... As I said by heart, the 4 or 6% sounded underestimated.
But unless I'm missing something, your latest calculation above is now over the top.
When you take into account the cosine/sine of a 20 degrees hull (or whatever), aren't you assuming that the thrust has the same angle?
In practice, IPS never reaches the same angle of the hull at cruising speed. Only if and when rotated 90° against the axis, the pod reaches the same angle of the hull, which obviously only happens when maneuvering.
In fact, your calculation fully applies in that conditions, and explains nicely what Daka reported about a flybridge leaning badly when moving sideways toward the finger.
If the same effect would also apply when steering at speed, we should have heard of quite a number of IPS boats capsized...!
Which btw makes another question spring to my mind: what if the IPS control box would go nuts at speed, suddenly rotating both pods 90 degrees in the same direction? /forums/images/graemlins/shocked.gif
That's phisycally impossible with ANY other propulsion system, 'cept maybe those very small o/b with no reverse, which can rotate freely (but they don't have enough power to be dangerous anyhow).

 

[MapisM]

[ QUOTE ]
IPS has brought a bold new world to boating and I would not be shy in saying so sold more boats than may have been sold previously certainly moved customers into bigger and more expensive models that they would not have considered before.

[/ QUOTE ]I agree Trev, 'cept that this is not (only) a positive thing imho.
OceanFroggie got it right, if you think about it: anyone who refrained from purchasing a boat (or a bigger one) just for fear of mooring maneuvers, obviously has no idea of what the real dangers of boating are.
And if IPS alone can give them the confidence to be great captains just because it takes the sweat out of mooring, well, I have two words for those captains and their crew, whenever they'll find themselves in really difficult conditions: good luck.

 

[Nautical]

I can understand that M, of course, but on the otherhand a goodly majority of newbies don't buy the boat that really suits them or their needs purely on the worry factor of berthing something bigger. So they buy a 30 footer first and then low and behold six months a year later there are moving out of it to buy the boat they really should have had in the begining, loosing a fortune in the process. If they can move into the right boat for their needs in the first place because pods give them greater confidence to jump right in then within the first season they are up the speed with seamanship, handling and overall confidence anyway just like any other new boater buying a shaft or OD boat. What I think we are missing here is that IPS in normal mode operates and handles exactly like any shaft drive boat, turn the wheel left to go port, midships to go straight ahead and throttles forward or back to go faster or slower. The only difference is berthing or close to at which point your speed is down to 2-3 knts, whats the worst can happen ?, dinked stainless or gel coat maybe if the joystick fails and there are plenty do that with painfull regularity with out pods or joystick .

In any event we always have new people to joystick practice without it, get a feel for operating on normal shaft drive mode and keep having a go every now and then.

We have all seen the newbie that bought a 50' shaft drive flybridge with all the bells and whistles, thrusters etc still make a shambles of berthing, dink, bounce, whallop off everything in the marina. As stated before I don't get this idea that seamanship is linked to what type of drive system you have, the only difference is that your berthing or close too work might be a bit ropey if the stick fails but its not life and death stuff! .