We used to get maybe a few requests a month for WB or Discharge. I bet its 2-3 a year max now. That fad died a bit in my experience. I can't even think of but 1 request this year so far. We aren't changing any time soon.
Think of your niche customer, they know the brand of oil in their car, but I couldn't tell you anything about how my truck runs.
Now think if your niche was working with retail brands following fashion trends, or wanting to be eco-friendly, or Nike or Adidas pushing PVC Free and PVC Free Plastisol is a bad product.
We get requests from customers constantly for water base or discharge as our customers are in the shirt business, your niche so it seems is motor heads getting a car on a shirt, they don't need to know or care about what ink, just want to them what is a good product.
If I printed for your demographic I wouldn't do water base, it'd be a nightmare and you probably couldn't do most of the work you do with the presses you have as it's too small for the high color work you do, not enough cool down, flash stations.
However I only practically sell water base as that's what I prefer and I sell / push what I like. It's harder, cost more, has more waste product, but creates a higher end product in my mind that I charge more for, and the customers pay it happily. We take 3 screens to do a "one color" white, but it looks / feels / washes / lasts damn good.
Our shop is probably like 70/30 plastisol to water base, however water base is growing constantly as 100% it's a better end product. Our problem is now we need a bigger press, or to get better at wet on wet / heat control. Anyone can do both, there are challenges to both, but I try to put out the best product that I can stand behind and for me it's water base hands down. Also can do water base and plastisol together nicely as well, there are no rules it has to be one or the other.
Nice boat by the way! Boat life is the best life.