Replying to Asking advice about a job decision (ASAP)

Okay Newschoolers I have 48 hours to make this decision
I'm a third-year mechanical engineering student in the co-op program at UBC, and have been working in a local ski and bike shop for the past three years doing sales/bootfitting/techwork. My dream career with this degree is to stay in the industry (skiing/biking), but really, I think I would be happy with any job that was manufacturing/R&D based. This morning I got an offer for one of the Co-op positions that I applied for, an 8-month placement at a marine engineering firm specializing in equipment for fish farming and mooring systems in Campbell River, BC. Not my dream industry, but the position sounds amazing as far as relevant experience goes – the company is really R&D based and provides custom solutions for clients so I would be mostly doing support on testing and design work for their projects and would be given challenging, degree-oriented work. To complicate things, I also got an email from a bike component manufacturer in Whistler today that I had called a few weeks ago saying that they have a position as a machinist available. When I spoke with them on the phone they said that they weren’t sure if it would satisfy my co-op requirements as it would be primarily just operating the CNC’s, but that was potential for updating drawing files and doing some modelling in SolidWorks as well. What’s making this decision so hard is that both positions are very appealing but for different reasons – At the machining job I wouldn’t necessarily be getting the same level of relevant engineering experience, but I would be getting valid experience in the industry and another foot in the door. The other issue is that it wasn’t a formal offer, more just saying that the position was available and they wanted to let me know after I expressed interest in working with them over the phone. Comparatively, at the R&D position on the island I would be getting great experience in engineering work, most of which would also likely be transferrable to the outdoor sports industry later on. I really don’t know which route to go down, and I only have 2 days to accept or decline the formal offer on the Co-op site. The pay for the R&D position is better, but I don’t know if I can put a price on the potential connections I could make from the machining position. I also really don’t want to turn down this formal offer to just to find out the other company has already filled the position or that I don’t necessarily bring the skills their looking for. One final consideration is I also don't really know where I stand on fish farming, it's kind a of a grey area for me and I don't necessarily feel comfortable facilitating it at this company. Any suggestions/ insight would be greatly appreciated.

tldr; As a mechanical engineering student in the co-op program, I have 2 potential jobs:
One is a formal offer for an 8-month term for a marine engineering firm based on the island focused on product development/R&D in the fish farm/mooring system industry with tons of good degree experience
The other is an email from a bike component manufacturer in whistler saying that they are interested in hiring, but no formal offer yet for a machining position (not as relevant of engineering experience, but much more relevant in terms of the career path I want to take)