This is an excerpt from the Chapter on Buddy Skills in my book, Some of it is geared towards finding a regular buddy but all of it can be applied with a little modification towards insta buddies as well. The key is not only honesty but being able to convey that effectively. The entire chapter does some accident analysis, describes how I train divers to have good buddy skills, and a few other key items. But this is appropriate here IMO,
From - SCUBA: A Practical Guide for the New Diver by James A Lapenta
"But what if youre a new diver who has not been around many other divers? How do you discover the best dive buddies and choose one who will be best for you? You can frequent local dive sites, join a dive club, and join message boards. You can ask your instructor to pair you with local divers and include you on trips; you can even ask to go along on checkout dives with other students after you have been certified. In choosing a buddy, you will need to develop a knack for recognizing the signs of a good partner and trusting your own instincts. Once a likely buddy is identified, you should dive together as much as possible in safe conditions where you can get to know each other and learn how to work well together.
Potential buddies obviously need to evaluate each others skills and training, but also need to consider each others interests and attitudes. Divers of equal skill and training do not necessarily make good buddies. One diver may love wrecks while the other may prefer reef dives. The skills junkie may not be a good match for the diver who is content with maintaining fair skills and just having fun. We may have heard that underwater photographers make less then desirable dive buddies, but they can be fun to dive with if we take the right attitude about the dive. Each dive with an underwater photographer is an opportunity to practice our buddy attentiveness, work on buoyancy skills, propulsion techniques, and observation skills. It can be one of divings more rewarding experiences if we choose to make it one. When choosing a dive buddy, we have all the power in the world. There is no reason to team up with someone who gives you a feeling of unease or concern. Its better to call the dive or hire a professional for the dive. When traveling as a single diver, we seldom have the time to get to know a new diver as well as wed like. Diving with what are affectionately known as insta-buddies can be fun, rewarding, and educational
or a disaster.
This means that we always, even when diving with a buddy, have to be prepared to save our own skin. We also have to be prepared to end a dive alone and get back to shore or on the boat if our new friend decides to deviate from the plan, disappears, or is just too scary to continue the dive with! Numerous issues can arise with these insta-buddies, including lack of communication, use of different hand signals, different goals, and different basic practices. Some divers seriously overstate their qualifications and skills, which does not become apparent until a dive has actually commenced. Unfortunately, this is a common occurrence.