As far as our Odyssey swimruns go, each course highlights a different skill set:
Casco Bay Islands, Maine: best course of the all-arounder. tough swims in ocean. can be cold water (as low as mid 50's in a few sections, typically low 60's in most areas). huge variety during the run legs. a few longer runs.
Les Cheneaux Islands, Michigan: swimmers course. Lake Huron can be quite tough, and also cold. there is only one short swim on this course. otherwise, all swims are 600-1200 in length.
Orcas Island, Washington: trail runners paradise. a few tough swims, especially on the back half of the course, but the run is all about your ability to manage your effort on some persistent hilly terrain!
Austin, Texas: this course will be a mixture but the swims will be shorter in length than our other races. the running will be a mix of undulating trails in Pace Bend Park and also some road running (also quite hilly).
Swimrun can be super simplistic with minimal equipment needed outside of a wetsuit, goggles, trail shoes, and pull buoy/paddles if desired. Or you can get as creative with the equipment as you'd like and get really specific on the strategy depending on the course. So much variety.