I look at some of the changes that are being asked for and I worry about the added weight they are going to add, over how useful they would really be. You do the same thing when you design a homebuilt aircraft… It all comes down to trade-offs. I would really like to see this little beast when you get the design done.

Kristine

I would build it with a slot in the aft section (astern the slider) hardtop for standing room, and ventilation, with a snap down cover for weather.

Of course it may be considered to slide the whole top aft, which may also be part of the removal process.

Yep, these along with the bow access and the boat becomes very friendly from a handling standpoint, and a recreation standpoint without losing utility.

Stumbled across your web page and I am very happy I did.
Can you advise the cost of the plans for the Gato 21 and 24
As well as the Largo model shown. We would like 2.500m Beam if possible.
Keen to talk with you in regard to Australian outlet for these hulls.
Judging from the feed back and your comments they are set for a winner.

Note take care when you add a door as it weakens the panel quite a lot.

Cheers Rodney

An attribute that I didn’t see commented on is the utility of the vessel for people in wheelchairs. It looks to me that a simple small boarding ramp might make that possible. And if so you may really have a winner.

How do you imagine she might be in a fairly rough sea with a lot of wind?
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Hi Jim,

A bow ramp is one of the modifications that the Largo will be getting, along with a split windshield and at least, one side opening (hinged door?) for loading when side tied at a dock.

The bow ramp will allow the Largo to be driven onto a shore (mud, dirt, sand, gravel) where the ramp can be lowered for exit and entry. This will keep the engines in the water for reversing off the beach.

In a seaway, as you describe it, I imagine that the Largo will be a bit out of her element but should be able to handle short periods like that with a skilled skipper. There are better boats for those conditions.

Chris

Chris

If that wasn’t bad enough you have trapped the engine noise inside the hull. Low frequency noise is hard to kill. I built a cabin on a boat with a friend (Alaska-Yukon River) You would have sworn that the boat was quieter when you closed the door on the cabin but a db meter indicated that it was actually 10 db louder under way due to trapping the low frequency sound and the added influence of wave pounding on the hull. The cabin cut the highs but had no affect on the lows. You can wear adequate hearing protection for up to 110 db high frequencies but the lows can’t be adequately stopped. This boat design is gong to get you in at least two ways. Think carbon monoxide poisoning and permanent tinnitus. (No dear that isn’t your phone ringing)
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Hi Dan,

I appreciate your comments on the Largo design study and will take them into consideration as I complete the final design work on the boat.

The exhaust issue has been considered for quite some time with this boat. One of the important issues with regards to the exhaust of these smallish outboards is that when underway, the exhaust exits through the propeller
underwater and does not get to the surface until the boat has moved along some distance. The only time that the exhaust does not exit through the prop is when the boat is not in gear.

The second issue I considered, was that the engine cavity will need to have a supply of fresh air so that the idle engine will not be breathing its own exhaust. Each side of the boat will get an air scoop of sufficient size to provide air flow into, and through, the compartment. The engine compartments could also see a pair of small, electrically operated fans that kick-in when the engine is out of gear to facilitate flow and remove exhaust gases.

Every boat of this size will have similar issues of vortex generated exhaust swirling back into the passenger area. The trick is to minimize the effect as best as possible. I have been looking at the solutions being used in the
automotive industry to prevent exhaust from recirculating and some of them hold real promise.

About the potential noise problems… The engine compartments will have sound absorbing material on all sides, save for the very lowest sections of the hull. Engine vibration is going to be present no matter what you do to
isolate the engine itself from the structure of the boat. Some vibration can be reduced through the use of isolastic mounts, but they are not especially feasible for the typical outboard engine. This means that virtually all boats with outboards will face the same problems of low frequency
transmission through the structure. I do not see this as a really big problem for this type of boat, as the engines are only 9.9 hp units and they will be operating most of the time at partial throttle settings.

I have specified Yamaha four strokes, because they are very well balanced engines, have low external noise signatures and due to their smallish size, will not be generating as much low frequency rumble.

If one wishes to reduce, substantially, the amount of transmitted noise as it is produced by the average outboard, then they might look strongly at going electric.

Electric motors can be equipped with vibration isolation mounts that are very effective. Electric motors are already quite a bit less noisy than are internal combustion engines and they represent some real design opportunities for placement of the weight centers for best boat
handling characteristics.

In the future, there will be a propulsion choice for Largo builders, as I will be specifying a battery/electric motor combo that will give a whole different take on the boat. Electric drive is not for everyone who may wish to own a boat, but for those who have a use
application which matches the capabilities of an electric drive, they will be able to enjoy the advantages.

The Largo is meant to be a step in the right direction for utility, boat balance, low fuel consumption and ease of trailering… all in a lower profile, more aerodynamic package when compared to the average outboard boat with a full cabin. It is not designed to plane, uses much smaller, and quieter engines which weigh considerably less and the weights are positioned forward towards the center of buoyancy of the boat providing a less pitchy ride.

No boat is going to be a perfect solution to all that a boater may wish to see in a personal craft. If the design meets your utility needs and satisfies your aesthetic sense of design, then it might be a really good solution for you.

I do appreciate that you have taken the time to post your opinions and will keep your comments active as I finish the design of the Largo, prior to offering plans.

Chris O

Chris

Chris

After all the really wonderful suggestions I have been getting about this design, the Largo concept re-entered the design study barn here at the studio compound, destined to be revealed again as a much more useful craft.

Largo will be back soon with a host of changes to include: hull side openings for entry/exit, a split wind screen for bow access, a fold down bow ramp for painless loading when the boat is beached and wider aft hull volumes for full engine movement as per Yamaha specs.

Chris