I have the 80lb on a 5 metre boat and it handles well even in big tides only issue I have had is swell. But if I stand at the front and fish it helps. Always go more power just check with your insurance company if they will cover it because from past experience it's something you had to add to the cover. I had a great chat to the guys in Darwin about motor guide vs Minn kota  from in and outboard marine

 Cheers mate, will have to look at it from insurance point of view too.. it's something most guys wouldn't bother with on a bigger boat but could really come into its own when deep dropping, jigging, bottom bouncing even..

what length shaft you running on yours? Looks like I'll be need a 72" which will hopefully get it deep enough in the water if there's a bit of swell around too.

I have the 80lb 24v 72 inch motorguide on my 6m fibreglass centre console (weight about 1500kg).   Very happy with it and the batteries last a full day of fishing easily.  I never use the anchor anymore.  The only issue I have is occasionally it will lose spotlock and I have to reset.  I suspect this is a satellite/gps issue.  Spotlock holds in 15/18 knots, but above that I tend to lose position as the bow rocks in the swell and the prop comes out of the water occasionally.   A longer shaft may improve this, but for me the space tradeoff is not worth it.  Not all that keen on bottom bouncing in 20 knots anyway. 24v is definitely enough power on my boat, but if I had a heavier boat I would go 36v.  Also, watch out for propellor fish when fishing from the bow, exciting to catch but terrible to eat.

Hope that helps.

 6.5m boat rreally you'll need the 36v.  I've got a 36v motorguide on my cruise craft explorer 625 and it's brilliant.   You certainly don't want to be underpowered though.  Do it once and do it right

 So theres a good 3 tonne of boat in the water. I did a double take when i saw it--I know a friend of the owner, must quiz him to see how it goes.

I understand that auto deploy is not needed on a CC, but you'll have to have it on a cabin boat. And most of the reported problems  seem to be around the auto deploy function. On a cab boat, being able to easily dismantle if it stuffs up offshore, would be essential, IMO. And the weight of the installation is a drag on performance, 24/7. Lithium batteries end up being a must for 36v systems, and now you are looking at an incredibly expensive installation. 

But yes, they could be very useful.

I think Yamaha have a new feature on big outboards to spot lock even for a single engine fit out?

It is on all electronic control models of Yamaha outboards. Looks good from the Video's. I want to see one in real life on the ocean.  

It is on all electronic control models of Yamaha outboards. Looks good from the Video's. I want to see one in real life on the ocean.  

Which it has to, basic physics---it means it would be holding your spot stern itno to any sea, which is fine if its calm, pretty useless if it is not. The spotlockers, driving from the front, will always hold you bow into the wind and sea.

Funniest post I ever saw on this subject was a yank complaining that his spot locker wouldn't hold him at a particular angle to where he wanted to be, it just kept swinging around to align with, surpise, surprise, the wind.   really disappointed it wouldn't "do what it was supposed to" Science denying Trump supporter, no doubt.

 from all I have seen, you need to charge the batteries, particularly the 36v models, from shore power. DC-DC chargers have been less than successful (?), because you are really running your engines alternator hard to get 24v from 12v output. Can you even get a 12v-36v DC-DC charger? 12v DC-DC is bad enough, with the inefficiencies of the things, ( only about 50% efficiency )you are running any alternator hard to supply them. 

So, on an extended trip away, you are going to run out of power after a couple of days, and they are then just ballast. I do a trip away, remote, of a month each year, boat stays in the water. So I'd have to cart a generator and charger out and run them on the deck? 

You don't need Auto deploy on a cabin boat.  You only need to be able to get to where the motor is located to put it down. And 3 x lead-acid batts does the job fine on my boat, actually helps the ride.  I would never own another boat without one.

 he's the bloke who installed it for him. 36v system, 72" leg. the 2400 is a big girl, but the motor does a good job of holding place --lifting out of the water can be a problem if the swell is big with just a little wind under it. I forgot to ask what brand it was . He reckons they wouldn't be without it, deep dropping and shallower stuff, out off NW Cape. They catch a lot of fish. He went lead-acid with the batteries--I queried this, it was a cost factor, but he reckoned they offset some of the weight by the removal of a large amount of anchor chain that comes standard, replaced with rope. And with the 2400 weighing something like at least 2600kg in the water, 90kg of batteries won't make a lot of difference--it is running twin Merc 150 4s.  He has it deploying out through the split bow rail. I don't think the Reefrunner  would like more weight in the bow--she likes to land on the aft half of the hull, and after excessive use of trim and trim tabs to " keep the bow low", which is conventional wisdom, I have learnt to trim neutral or higher, with no tab, and just let 'er rip. Going too slow and throttling back when you sense yourself getting air  is the wrong things to do. 

After all of the exercises in frustration I had trying to anchor precisely in Exmouth Gulf, with wind vs tide, I could see it being very useful inside there, too. For me, really just the need to re-charge from shore power would be a problem--fine at home, but I'm guessing a month at Winderabandi would mean carting a generator out to the boat every few days for a re-charge. On this topic, people generally say " they go all day without a problem"  . If you were only bottom bashing for a couple of hours a day, with batteries of recommended capacity, just how long would you go between charges? 

 Lot of variables but I cheaped out on batteries, 3 x 105 amp/hr lead acid.  I had one day fishing from 6am until 9pm and the battery light was still green.  What that actually means I don't really know but it was still holding us no probs.  625 cruise craft in under 10 knots of breeze with light current.  If only fishing a couple of hours per day I reckon you'd want to charge them every third day to avoid giving them too much of a hard time.  Mine is a motorguide 36v and I made my own bracket out of stainless I had lying around.  Total cost for motor, batteries, circuit breaker and cable was about $3800.  I'll Get a decent battery charger when I get around to it so I can charge all three at once.  

What about using one of those red arc high end chargers  to keep batteries maintained 

you can use solar altinator and power  to charge...so solar to charge while fishing or parked up, alt to charge when driving. And power to keep topped up at home...they fully data log aswell use one in my cruiser they are mint 

 Easy if you are using 12v, less choice with 24v, any choice at all with a 36v system? I need to do some research.

Edit--Ok, there are 12v-36v DC-DC chargers in Australia.  www.outbackmarine.com.au/pro-charge-b-series-12-36-volt-dc-to-dc-battery-ch But the only one I can find is not suitable for lithium, only older types. Still looking.