Okay, Okay, before the rush of emails crashes the server let me say that commercial electronics will always have a place at all levels of the industry. There are some good reasons for a strong open source community including several that strengthen the existing manufacturers.
First let's look at open source which is very misunderstood. Some people assume that the "free" software a friend installs on their computer is an illicit copy. The idea that someone would put the time and effort into a piece of software and not expect payment is odd to most people.
Yet this model is thriving, with some growing pains, in many advanced hobby environments. Some of this is open source hardware as well as software. Recreational boat enthusiasts are also making projects including sensors and innovative display solutions like repurposed e-reader displays that have large, bold images that are viewable from a distance in strong sunlight.
Another very successful open source project is the Open ROV which quickly evolved over the past few years to become influential in affordable ROV design.
These designs are presented online and a community of interested amateurs refines the product through trial and error, theory, and design. Some of these amateurs are actually students who can model fluid dynamics like it's a reflex. The skill level varies but good communities get new people up to speed quickly but patiently.
This leads us to the first doubly positive situation that can come out of an open source marine electronics community.
Public Exposure - Few kids grow up wanting to design pre-heater fuel flow sensors. Many kids grow up wanting to work with ships and boats.
One of the big reasons that the shipping industry has stagnated in some countries is the lack of public exposure. Ports now have restricted access with a perimeter that keeps casual ship spotters out. The possibility of a ship tour is out of the question for interested port visitors since secure identification like a TWIC or other mariner's identity card is required for entry.
Not even a generation ago school groups might see the bridge of a ship or attend a launching ceremony. This is no longer the case so few students have marine electronics or other ship operations on their radar.
Open source communities often include school groups who build their own version of the project. Some of these classroom efforts are sophisticated since the instructor has built the project many times.
As these students enter later education the marine electronics industry is already a possible career path. What is it worth to the industry to have first year engineering students who have already routinely interfaced projects on family boat or in a high school project?
Community Support - Commercial and Open Source Playing Together!
Some manufactures have chosen to support well organized and stable projects with great public relations results. In the robotics industry Willow Garage uses an open source operating system which is freely distributed on their website. Researches and hobbyists both use and contribute to the software development.
Cultivating an image as a developer friendly company or organization might not be at the top of most corporate to-do lists. The people in charge of these sorts of things might want to consider the loyalty that is often developed for a certain brand. This translates into sales of commercial products when something more sophisticated is desired.
Potential Issues - The Things that Go Wrong
Devaluing Paid Workers
If some skilled hobbyists will produce a product or documentation for free the product managers, engineers, and fabricators could experience real or perceived devaluation. Additional marine electronics workers will increase supply and therefore decrease salary.
If you read anything about intellectual property you know this is a mess in the USA and other places. This is the weakest point of open source and the is the reason for a lot of spirited debate.
Open source projects rely on a license which allows production without profit and requires changes be documented. Each version of the project is in turn licensed with the same rights. This makes the concept of Prior Art, which is the basis of many patents, difficult or impossible to work out if a commercial version is planned.
Argument and Fragmentation
When you get smart, passionate people together tempers flare, feelings are hurt and sometimes a project will form two or more "branches" which are slightly different ways of doing the same thing. Some branches thrive, some are abandoned as graduation or a new job takes top priority. The best example of this is the Linux operating system which has many different implementations using the same core software.
Safety and Certification
This is a huge concern for the maritime community. You will not get that mess of poorly crimped mystery wires past your surveyor or the coast guard. This means that you will not be able to obtain insurance or possibly operate legally.
Most of the big negative influences can be mitigated with careful planning and management. Some open source communities are started and controlled by individuals. Others have carefully documented group efforts with properly elected board members and controlling officers.
The open source marine electronics community is already forming and it will be interesting to see if a notoriously secretive industry can harness the power of the open source movement to lift it out of the doldrums.