It is more a question of ethics than legallity.

Ethically you should probably acknowledge the inspiration for your new design, however Necky may take offense because they may feel you are using their trademark to help promote your boat. It is a fine line between being ethicaly honest and sticking your butt out to be kicked.

I would proceed by drawing up a design inspired by the boat you like. Don't take anything more than rough measurements (instead of tracing forms directly from the boat) and proceed with your changes. If anyone asks why it looks so much like a Tesla, tell them what you did.

If you are just building for yourself, the ethics equation is a little different than if you sell the plans.

Using existing boats as inspiration is the only reasonable way to come up with a new design. It is virtually impossible to do otherwise.

For the record, my inspirations include the Dancer, Islander, Nordkapp, and Chinook. Some of the inspirations where negative, i.e. "there is a feature I DON'T want." The only one of these boats I had on hand to look at while I designed was the Dancer, an 11 ft white water boat. It provided positive ideas.

> I was wondering about the legality of copying a commercially
> built kayak and making a modified woodstrip version for personal use.
>

> This came up when I got a kevlar Necky Tesla last year from somebody
> who bought it new, used it a couple times, and discovered he hated
> kayaking. Why he didn't start with a plastic boat I can't imagine.
> I can't complain since I got it for less than half price. Even though
> I already owned 7 kayaks I couldn't turn it down.

> Along with my wife and various friends, I have built strip boats
> for years and since I really like the Tesla's design I started wondering
> about modifying and stripping it. It is a high volume boat and I am
> a high volume person (6'2"/220lbs) but it isn't overly large
> like some other high volume boats I've tried. I am very comfortable
> in it, especially after I installed my own seat, and it handles very
> well. I was looking to build another boat this winter and I started
> wondering if it would be legal to build a modified Tesla.

> The boat is a good starting point but I think I can make it much
> better. I would change the hull design a bit taking out some rocker
> and moving some volume further forward. Probably make the deck shape
> differently also. It would still be based on a Tesla though hence
> my concern about copyright laws. I certainly don't want to be accused
> of stealing anything from Necky. How much of a change constitutes
> a new design? Can you legally start out with someone elses design
> at all no matter how much you change it?

> An extreme example; how about a car? Could somebody legally build
> a wooden Volkswagon Beetle for their personal use? If so what's the
> difference between that and cloning a boat?

> I realize that if someone were to mass produce and sell the strip
> versions or publish plans of a Tesla (or a Volkswagon) there could
> be a huge problem. Realistically I can't see Necky wasting time and
> money taking one person to court for a boat made stricly for personal
> use but you never know these days.

> It is an interesting question, any thoughts?

> ~Edgar Kleindinst