It potentially can be possible if you provide your capital to a fund who operates as a private lender.You would have to be a non-managing member in an LLC or an LP in a Partnership.Therefore, you would have no say in items such as who to lend the money to, at what rates, etc.Best of luck

The houses they buy are in non-flood zone.

From talking to locals, there's a couple of issues than need to be addressed, some are the non-ecological practices that some of those developers have, unfortunately, our government profits from this investors and allows them to destroy manglers (which are the natural water purifying system of that area) dismantling hectares of mangroves and degraded the habitat of resident and migratory species burying animals alive.There's proof of fecal material floating beneath the city of Tulum, only 20% of the water is sent to the water treatment plant, there's no infrastructure for the exponential growth.The landfills in the middle of the jungle that is leaking hazardous pollutants into the freshwater system and that something that developers won't tell you.I love my country and it would be a disaster for everybody if this place ends up like some other great beaches around the world, that are completely ruined by greedy investors not following the rules.There's no urban or comprehensive master plan, and one of the risks is that Tulum will be like Playa del Carmen is today, overgrown and with environmental devastation.I will advise doing a lot of research before getting something in Tulum, different country, different rules, and practices.

Equity paydown and modest appreciation would result in a small profit; not enough to justify a non passive investment but i will own a killer cabin.  

Your expert (the plumber) couldn't confirm the cause.

At that point, the small down payment is a non-issue. 

I went into two of my listings (one with a flexible cancellation policy and one with non-refundable) and it is pretty clear what the terms are BEFORE booking.  

We don't charge any  up-front fees for this and it shouldn't be necessary, but do watch out for the upfront non-refundable "commitment fee" or "engagement fee."

But my market is still better because of my team and our personal enjoyment of non REI.  

Following advice, I put $130K into a charity fund to start a 501(c)(3) non-profit.