Pure Watercraft Launch

While we’ve been working hard at this for the past 5 years, now is the public launch of Pure Watercraft and the Pure Outboard, with pre-sales of the Pure Outboard open now.

Our team of experienced, dedicated engineers has been working on revolutionizing boat propulsion from the ground up. The result is an outboard motor vastly different than the ones on the market today, and far superior for many applications than gas-powered alternatives. Pure Outboard is the first step as we strive to bring boating to a new level of performance, convenience, and enjoyment.

Welcome to a new era of boating.

10 Comments

Rich Schineller

April 13, 2016 at 8:35 am

Very excitied about this, especially for appicability to crew and water recreational activities in our region!
Well done!

Martin Kuhn

April 13, 2016 at 11:44 am

This looks like a great product! – it addresses a real need

Here is some feedback;

(1) You may know this already, a number of European countries prohibit the use of gas powered outboards on lakes and inland waterways for environmental reasons. This limits fisherman to very small outboard electric units and other users to custom leisure craft which are very expensive. Your solution could significantly expand this market.

(2) As weight is less of a premium in boats, have you considered sealed lead acid batteries, which are much cheaper? (i.e. as used on diesel electric submarines)

(3) Are you using water to cool the electric motor and the batteries to enhance performance (especially during rapid discharge when cells can get very hot)?

(4) This is a great first product, which has similar physical dimensions to a gas powered outboard, but one which can be copied. Have you considered using the unique characteristics of an electric motor, which cannot be replicated by a gas motor – for example an aqua jet pump to enable zero draft operation, which is also safer and enables boats to easily go onshore?

Andy Rebele

April 13, 2016 at 3:44 pm

Martin, thanks very much for your thoughtful comments.

Weight is at more of a premium in boats than in cars. In cars, almost all the resistance at top speed is air resistance, which has no dependency on weight. In displacement boats, the total displacement is proportionate to weight, so the power required at full displacement speed is also a function of weight. In planing boats, the resistance is a function of the wetted area, which is a function of weight, so it is very highly dependent on weight. The highest performance cases are the ones we are designing for, since they are difficult to do, and if you solve them, then you have also solved the easy cases. You suggest using lead-acid batteries, and they are indeed much cheaper than any lithium chemistry, but there are some factors that mitigate that advantage: 1) you can only use about 60% of a lead-acid battery’s capacity without seriously impacting cycle life, 2) lead-acid cycle life is far less than that of lithium ion, 3) lead-acid is subject to higher “sag” during high discharge, so you never get the rated energy out of the cells when under high load, 4) the weight leads to higher displacement and higher energy consumption regardless of boat type, so their use drives a higher kWh need.

So there are three reasons we don’t do lead-acid: 1) it’s easy, so easily copied,2) it will never lead to high performance, and 3) the cost per effective kWh of use (taking into account cycle life and sag) is already almost as low for lithium ion as for lead-acid, and within 10 years lithium ion will overtake lead-acid in cost effectiveness (since lithium ion is improving in capacity by about 7% per year).

We use the water to cool the motor, gear set, and power electronics, but we have a different system to cool the batteries. We use a phase-change material to limit the cell temperatures during discharge, and we actively remove the heat during the charge cycle, taking advantage of much cheaper grid power. This enables us to implement our system on arbitrary hulls, instead of depending on a specific hull design to integrate our battery cooling mechanism.

A jet drive is less efficient than a propeller drive, when the aperture is fixed. The speed of our boats varies, so can’t achieve the same efficiency. For other reasons, like the one you pointed out, there may be reasons to implement a jet drive, but it will come at a cost of efficiency (vs. propeller).

Thanks again!

Andy

Jack

May 29, 2016 at 4:50 am

Bold vision, great potential … need harder figures on total cost of ownership … motor, battery packs, charging stations, etc. … and total weight of system compared to outboard. Thank you for being a thought leader … are you collaborating at all with Tesla?

Ross

June 5, 2016 at 1:18 pm

Nice job guys…well done….wish you the very best

Jay

October 27, 2016 at 5:58 am

interested but again hard numbers on a complete package is needed

antonie van Dillen

October 29, 2016 at 6:29 am

Do you have people with technical knowledge on “battery electric drive systems”? Any off the shelve packages for complete systems? How are the safety regulations for electric systems on the water? Do you need to be certified to install systems on boats?
As an electric engineer, I am very interested and have already made an overview of what is available in other countries. Installing is a challenge for the “do it you self” installer.

I will follow your blog with interest. Antonie.

k murray

July 15, 2017 at 8:45 am

Installation, cost, charging time, run time, and more keep me from sending you the $500.00 deposit…however I am most interested in the product and will keep checking back to see how production is coming along……

Andy Rebele

October 12, 2017 at 8:25 am

K Murray, installation is much simpler than with a gas outboard. First we mount the motor on the transom, tighten the clamps, and fasten the bolts. Then we place the battery packs in an appropriate place on the given hull. There is a single cable connection between the outboard and the battery pack, and a single cable connection between each battery pack (if using more than one). (Note: our prototype in the video uses two cables, but our production model uses a single cable.) The steering cable (standard cable steering) and our own drive-by-wire throttle are then installed. Installation of our system on a new hull by our team takes two people 20-25 minutes or one strong person 30-35 minutes.

Charging time depends on which of our chargers you use. If you have a system with two battery packs, and use half your charge, then it will take 6 hours to recharge with our 120V charger, and 1 hour to recharge with our 240V charger. Run time depends on your hull, driving style, etc., but we get about 31 miles range at 9-13 MPH in our test hull (a Still Water 25XL).

Jack asked about total cost of ownership. Good question. Our system will cost about $18,000 for two battery packs and an outboard. The annual fuel costs for a daily boater who currently uses $1,000 of fuel per year would go down to $250. The maintenance costs go to $0. The expected lifetime of the battery pack is 1500 full cycles, so it should last a daily boater using half the battery every day about 10 years before it has lost 20% of its original capacity. The outboard itself is designed with parts rated for 20,000 hours (vs. 4,000 hours for most gas outboards). Add it up and you get about $1750/year total cost of ownership for a daily boater, compared to a 40 HP gas outboard TCO of about $2500-3000/year ($500/yr motor depreciation, $1,000/yr fuel, $500-1,000/yr maintenance/repairs).

Antonie, you’ll have to check the regulations on installation in your country, but our system is designed for simple, safe installation. We use a single connector, IP67 waterproof rated, and our connections include an interlock loop that ensures that no high voltage leaves the battery packs without constant confirmation that all cables are properly connected.

Gary Singleton

October 13, 2018 at 12:49 pm

“…the things you will hear…”
Really? All I hear on this website is obnoxious (IMO) generic synthetic “music”.
Jobbed-out website? Fire them. Maybe follow through with your own jive and treat us to some fish jumping, geese pealing out, air-borne dolphin banter, crew grunting…anything.
As it stands, twin outboard Mercs make a sweeter sound than your soundtrack.
Now don’t go changing the “music” to something with more “universal appeal”…no matter what you pick someone will hate it, duh. Can it. Present a key aspect of your (fantastic) concept, and best of luck!

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