If you do not have anyone yet, I would love to help. as Bob Crane mentioned.  There are good and bad agents in the area and I would caution against some of the major franchises.  I am traveling right now but would be glad to call you this evening.

Buddies are great to have but you must now find a great associate there to refer him to. There are plenty so your work is cut out for you to do that plus keep him as your buddy.

 You can refer him to a Realtor in Playa Del Carmen for a referral fee.  I'd go to Google and see what I could find.  Also, if your company has any affiliations with an international referral organization, go through them.  

Refer him to someone who knows this area, try Gary Coles (International Referrals) 

Pete Roszell - refer your buddy out to someone in Mexico  (not sure how that would work, though.)

And you are there to help your buddy take right investment decisions in Denver, CO....

How about a referral agreement?

Refer him .

I'd say just be careful and make sure to pay the appropriate fees.

YOu can find a local agent and get paid your referal fee. As for advice, please do not give any advice. I just spend hours answering email for my out of state client who has a lot of experience with RE and his local trusted realtor, but our customs are different, our markets are different, our contract and disclosures are completely different. 

Be careful, I've referred to Mexico and a few other latin american countries and got stiffed  -  I no longer refer there

refer it to the top agent in his area....

Refer.

Referral prospect only!

Refer it ... however complete your due dilligence on the agent you refer to ... get the terms in writing.

referral out

Find a trusted real estate agent in that area and collect a referral fee.

Mexican Real Estate answers to no one in America and iffy in Mexico too

As others have suggested -- refer good local real estate representation.  Good luck to your buddy.   

Refer him to a local agent for a referral fee. 

I'm sure you can refer him out but don't know what international referral fees are. Interesting thought.

RM has offices in many countries but never thought about this.

Referral

Kevin J. May nailed this one!

I agree with all the answers you already received regarding referring this to an agent in Playa Del Carmen and asking for a referral fee.

I'd also make sure to get invited down to the properties before they go on the market to take a swim or something.

Referral to a good local agent and contact any possible buyers in your network.

 Find an agent down there and wait for him to that agent ....

Definitely refer them to a well-researched, reputable agent in Playa Del Carmen.  Then, take a trip down with them for the showings and enjoy a little vacation!  

Probably finding a great agent who works that area, either from the US or in Mexico, to refer him too. I imagine Sotheby's International has a brokerage there

Find a reputable agent for him and do a referral.

Try finding an agent to refer him to in that area. This sounds like it could be a good deal for you. Take some time to interview several agents to find just the right one for him. 

If you ever need anything on the Western Slope of CO...get in touch with me. I love referrals. 

Refer him to a real estate agent in Playa Del Carmen.

Pete make sure you go with a US national company that has offices in PDC, I know a couple if you need help private message me Endre

There's a lot of removal of words from one's mouth going on here.

Very unsanitary.

Patricia Kennedy took the words right out of my mouth!