https://www.by-the-sea.com/stimsonmarine/bowroof.html
Via (basically, a review of building above as shed for working on a boat):
http://www.microcruising.com/shed.htm
I'll take the liberty of quoting some of the first page in greater detail here in case the link goes away (but judging by the style, it appears to have been around a long time):
Has anyone built one of these or something like it and used it for gardening? I came across it in the boat context but the price and the ability to withstand such weather conditions makes it interesting to me (although I don't have any land to erect such a shed/greenhouse yet).Build your own BOW-ROOF GREENHOUSE/SHED easily using our complete, easy-to-read plans and step-by-step manual. Great for greenhouse, boat shed, workshop or garage.
The 14' x 32' greenhouse/shed pictured here can be built in 40 hours and $400.00 to $600.00 for materials depending on your location.
For the past nine years, we have used these elegant structures as season extenders for growing tomatoes, peppers, and other vegetables. This winter for the first time we are growing cold-weather crops in a cold-frame inside a Bow-Roof Greenhouse/Shed. The sun is our only heat source, and yet we have a good crop of kale, spinach, lettuce, and swiss chard growing here in Maine in January.
Bow-Roof Greenhouse/Sheds are designed to withstand strong winds and heavy snow loads. Ours have stood up to 70 mph winds and have had snow piled nine feet high on the sides without collapsing. The low cost of materials, and ease of construction make these the most economical of any shelters we have ever seen.
The Bow-Roof Greenhouse/Shed pictured here is used as a storage building. We've also used these buildings as garages and temporary workshops. Our plans will tell you how to build a shelter of any width from 10' to 20' - but 20' is the widest that we would recommend for this construction method. The length is up to you - 20' to l/2 mile!