Old used Aerotec impressions.

[Fenlander]

Well after that extensive re-glue and patch reported in this thread...

http://www.rib.net/forum/f50/aerotec...ice-68545.html

it was time to get it wet. On holiday now with easy access to the water so an ideal trial situation.

Usual easy inflate of an air floor type. I must say all these years on there is still a fascination with pulling a bundle of "fabric" out of the car and not too long later whooshing off on the sea.

Just one 8Nm run so far on the first day. Thankfully all the glue held!

Like our existing Zodiac 340 Acti-V I believe when lightly loaded (self plus teen) speed is limited by our 9" prop pitch on the 15" Mercury. Two way runs achieved a similar maximum to other air floors we've owned (to be precise from the GPS reading) with 17.9kts last night... and a one way maximum of 18.6kts. A nice cruise was around 15kts.

What was an improvement on the "flat" air floors was the ability to keep up the cruise into more choppy waters. It was super calm when we started out but halfway down the loch on the return there was the usual Scottish effect of wind funnelling between hills producing an awkward chop 45deg off the bow which it ran through well just with the odd squirm.

Anyway have to collect a kayak for daughter so a few images for now and more to say later.

Edit: Btw even with the initial 20mm transom shim it's a splashy thing!

[McNish]

Good stuff, cheers. Have just done extensive repair work to a 340 cadet, it's a great felling when they're up, running and dry inside.

[Fenlander]

>>> running and dry inside.

Leak wise you're right but splash wise it's a different matter. Swapped for a 26mm transom shim for yesterday's run of 15Nm.

These Aerotecs are certainly sensitive to outboard settings. I didn't try it without a shim but went straight for the 20mm on first day which still splashed a bit of water over the transom and there was a hint of intermittent cavitation in a turn.

The 26mm shim had less splash at 14kts but more flat out... and not a sign of cavitation... odd. Today I'm going to try it with no shim and then just over 30mm.

I always said we couldn't have an Aerotec due to the sloped floor not suiting some minor mobility issues my wife has suffered in the past but which a recent op has reduced. So this was one of the biggest aspects of the V floor vs flat floor trial this holiday.

Thankfully she has no problem with the mostly angled floor now. The dog who is a constant boating companion is not so keen though as once you take out the area of the strapped down fuel tank there is a relatively small area that's flat for him to lie on. Also we've had to work out a different way of storing our kit as it all falls to the centre.

I would agree with a comment Max has made in the past that there is a slightly increased feeling of security with the greater internal depth from the V floor.

I was pleased to find on this latest 15Nm outing we didn't have to drop off the plane once due to sea conditions which would have been a factor with the flat air floors and hard floors we've had over the last decade.

Also speed was not too badly reduced for upping the load from our lightest to whole family plus dog and kit... about 37st in people/dog plus 20l fuel and usual kit. Comfortable cruise was down a little to 13-14kts and maximum seen 16.3kts.

So.... an Aerotec success as far as I can see... apart from the wish that splashing was easier to sort.

Just one image attached... of the splashing with the 26mm shim... you can see just behind my arm water throws up over the tube ends and every few seconds this reaches over the transom.

[Max...]

Glad you're enjoying it. I think you will find whatever height you set the engine at you will get splashing - from looking at this in the past on here the unique Aerotec V that continues to the transom seems to channel water onto the leg and altering the height will not stop this.

However, this should not be coming over the transom with a 25mm or so shim. I don't think you can go much higher without modding the transom plates as the turnbuckles will be too high.

And as you note increasing the height will lead to ventilation in sharp turns sometimes, can't be avoided!

I'd strongly recommend doing the rubber floor mod, this firms up and flattens the floor - makes a big difference.

Also loads of places on these to clip on dry bags, fuel bladders etc to free up floor space. I clip ropes and bags to the bow rings and these tuck right out of the way in the forward bow space. And don't forget the 'storage pocket' under the floor - I carry the oars and 50ft of rope in there.

I think the thing to remember with the Aerotec is that it's marketed as a 'sports SIB', hence the narrow beam, 'performance hull', 45cm diameter tubes etc and really comes into it's own when driven this way (sporty) - ie rough water, chop, sharp turns at speed with much less slip etc.

[Fenlander]

Something I've not picked up on yet... is splashing more of a problem with the 380/Mercury combination?

[Max...]

Possibly, check Loco's ABC SIB/engine set up topic for this. As long as the CAV plate is the correct optimum height not much else you can do...

[chipko]

Spotted this on a fairly new Aerotec last year. Don't know if it's a Zod/Bom accessory or how effective it might be, but looks a neat fitting.

[Fenlander]

That looks interesting. Is it a metal bracket with a rubber bit that would press against the front of the outboard and stop most of the water hitting the lumpy bit of the outboard?

[chipko]

Yes, quite right. Powder or plastic coated folded metal bracket with flexible rubber membrane to seal against lower leg.
Not got one on mine though as seem to have reduced splashing (not quite eliminated) to an acceptable level. Might be lucky with more credit going to the lower leg profile on the Suzuki DF20 as I think excessive splashing is a quirk of the hull/transom profile.

[Stevem]

As already stated i clip bags onto a line across the grab handle to keep the deck clear. Ive found these cycle panniers work quite well and are a good size, oh and halfrauds were selling them off.

[Max...]

How do you find the engine Chipko? - WOT/pick up/fuel consumption etc? That DF20 seems to be the default choice now if going for a 4 stroke.

[Fenlander]

Interesting re splash guard and storage bags ... thanks guys.

Main reason for buying the old Aerotec was to take it on holiday with our Zodiac 340 Acti-V for a back to back test and find out which suited us best. In another thread Max and I mulled over how the comparative performances might work out.

Today we mostly used the Zodiac so now have the figures.

Flat out the Zodiac with a light load recorded 19.1kts so 0.5kt up on the Aerotec but broadly very similar. What was very noticeable was the Zodiac in comparison had a far more pronounced "getting over the hump" period to get on the plane. The Aerotec would hop on the plane in a second or two as it passed through the transition speed but the Zodiac (as with all flat floor SIBs I've used with 15hp) would hang in the pronounced bow high position for several seconds before it flattened out to a true plane. It was very noticeable the Aerotec would passs through this transition both to and off the plane with an almost level attitude.

With the full family load this difference was even more pronounced and the maximum speed was down a little over the loaded Aerotec at 16.1kts.

Of course no transom splash issues with the Zodiac.

Today quite a bit of our time was as "safety boat" to our daughter sea kayaking for the first time. There is no doubt the flat floor of the Zodiac made it very suitable to a more family based activity with the dog able to stretch out in various places on the floor and similarly more space to put our kit about the place.

Nothing to do with the boats as such but the Zodiac has superb HD Trem folding type wheels which I find so useful and well made... but they remind me how much I like the clean look of the Bombard with its bolt on non-folding ones removed and left in the cottage.

Yep... really interesting to be able to properly compare the two boat types.

[Fenlander]

Max putting this here as I don't like to clutter sales/wanted threads...

From my current experience with the Aerotec/Mercury 15 combo I think you could discount the 8" pitch unless you were going to take our a far far heavier load than your usual. I think even with your full family and kit plus full fuel load an 8" would serve little purpose.

A 10" though would be interesting because it was obvious with ours the outboard would be capable of a faster boat speed when our people load was only myself plus light daughter.

[Max...]

Cheers David, will bear that in mind, and nice comparison. Do you think you will keep both boats? As we all know the perfect SIB is a combo of Avon Hypalon build, Y Class mahogany ply floor, Zodiac Fastroller lightness and Aerotec V hull/handling but it's wishing for the impossible.

[chipko]

Originally Posted by Max...

How do you find the engine Chipko? - WOT/pick up/fuel consumption etc? That DF20 seems to be the default choice now if going for a 4 stroke.

I've had the engine 2 years now and has been faultless so far.
Main reasons for buying was lightest at 44kg and the only 20hp with battery less EFI - 2 years on these benefits still apply.
Run mine on both 3.5 Zodiac and 3.8 Aerotec and often towing 18 year old son on a kneeboard. Solo will power both boats around 24/25 mph and two up towing kneeboard 21/22 mph. Very good hole shot and has no trouble quickly pulling kneeboard on to plane. If we didn't tow regularly I would up the prop pitch, as with the standard 9.25" x 10" it easily hits the rev limiter even two up. We briefly had an F-Rib 375 and really felt underpropped on this!
Not sure how economical it is compared to other 20hp four strokes but 10 litres will last a good 3 hrs for general hooning around - not towing but using lots of throttle!
Only downsides so far is 1 year less warranty at 5 years and slightly more vibration noted at low to medium revs.

[Fenlander]

>>>We briefly had an F-Rib 375...

Oh do tell!

>>>Do you think you will keep both boats?

Decisions decisions! There's been much chat at the moment over an evening meal after our days out. Back from hols on 25th and in truth if we're going to sell anything it needs to be soon after to catch the season. But there is a fair chance there'll be a nice 340 Acti-V with Mercury 10hp and Trem wheels up for grabs.

[Fenlander]

A new Aerotec experience yesterday evening... a solo run while I again carried out safety boat duties for daughter in kayak..

Wind was building to around force 5/6 (we had 8 overnight) so perhaps not the best situation for a solo trial. Anyway it felt far more lively than I was comfortable with so not the time to undertake speed trials... I was pleased when daughter gave up on the kayak and joined ship as ballast and we had a whoosh about until it became too wild and even the windsurfers had gone in.

We've refined where fuel tank and kit are best placed to get the perfect balance now and I'm increasingly impressed by the way it hops on and off the plane so easily with such an easy level transition.

I forgot to bring my tools to think of lifting the outer transom wooden pad and inner metal which would need doing in I added another shim so don't really want to go above a 26mm so it seems we'll have to live with the splash... but we do get the water to about the level of the floor panel joining piece after an enthusiastic hour out.

[Max...]

Have you got a tiller extension on it? Makes a huge difference, I think they are essential for weight balance and control on pretty much all SIB's but especially these circa 40 kg airfloor models - as is essential ballast up front (fuel, passenger, anchor/gear/pelicase etc). Certainly in a strong head sea, F4+.

PS, are you now an Aerotec convert?

[Fenlander]

Aerotec convert... ha ha. I have always appreciated them for their performance and it was only respect for Mrs F's previous difficulty with the angled floor that has kept them off the list until now.

So this release into a position to try one in proper conditions for two weeks was very welcome.

Overall we can offset the minor annoyances of a less than practical floor shape for dog and family... plus the splashing of course... for the ability to plough through more difficult conditions with confidence. We do not seek any more speed so the 15hp is still... for us... the best motor so I'm pleased to be able to keep this Mercury as finding a new engine is almost harder than the boat.

So yep... have to admit it's all worked out to be the best combo for the next "X" amount of years.

[Fenlander]

>>>Have you got a tiller extension on it?

Missed this. No I have one here but in extreme conditions I find the slight remoteness of an extended tiller offsets the benefit of balance... in truth it was too windy to do any experiments... to get back to the pontoon the right way up was enough.