I've been really scratching my head on where to find a trailer that is 1) long enough for a 15 1/2" boat, but 2) is meant for a very light load, not 1,000 lbs. Most trailers big enough have stiff springs to accommodate lots of weigh. I'll be surprised if my Goat and all it's gear adds up to much more than 200 lbs. and stiff springs will seem like no springs at all.
Then, I did a routine check of Craigslist and found this baby very near by. It was made by a boater to accommodate his homebuilt 14' wooden rowboat. Karma? Could be...
I'm particularly happy with the suspension because it looks to be well suited for a light load:
Not shown in this picture is the shock absorber that should prevent bouncy behavior. Overall, the trailer is rough. Some ugly welds, previous repairs, and rusty spots here and there. But it fits the bill for what I need now and can serve as the basis for continued improvements. And at $150, it's easily half the price or less of any new trailer I can find that is not as well suited as this.