OC Triathlon Review – An Annual Mission Viejo Lake Event (Update for 2023)

For 2023 OC Tri Runners. As of April 23, 2023 the lake was in 68-69 degrees. Visibility is low as always, you can’t see the bottom clearly past the beach. Locals also noted the lake can still cause Swimmer’s Itch, so be sure to bring soap and shower after the race. On race morning before the sun is up it should be cold enough in the water to wake you up, but not so cold to be an issue. Good luck everyone!

We have covered a number of triathlon related topics on this site, including how to train and pack for triathlons and even how to select a good one. While we fancy ourselves as triathletes, we recognize that our experience is limited given there are thousands of races across the globe. Having only competed in a small number of those, there are a few that stand out as fun events and align to schedules.

One of those has traditionally been the Orange County Triathlon, held annually in Mission Viejo. The race is an Olympic Distance event and, despite some hills, is a fun event and a good test each year to gauge fitness. It is also a local race for us, which means packing for it is easier – check out our whole guide on packing for a local triathlon.

While other events have better logistics, bigger fields, and arguably better scenery, this smaller well organized event is the perfect litmus test and has never failed to deliver on a great event. Below is a review of the event, based on the back to back experience of a Fall 2021 and Spring 2022 running. The typical event is run in the late spring each year and the unique 6 month back to back only came about due to the lingering cancelling of events in 2020 and Spring 2021 due to the pandemic.

orange county triathlon logo

OC Tri Course Overview

Open Water Swim in Lake Mission Viejo

The OC Tri course starts off with a swim in Lake Mission Viejo. Because the lake is so shallow, and the weather in the area mild, the conditions are near perfect for a swim. With only around 400 total entrants in the field and waves going off every 3-5 minutes, there is plenty of room to navigate.

Water temperatures in the lake are typically in the high 60’s degrees and with minimal changes even when the event was at the end of an unseasonably cold few days. Many competitors choose to wear wetsuits, but there are plenty who are just in tri kits or standard swim suits.

Visibility in the lake is not great, but without any waves to deal with spotting the large buoys is easy. In addition since the swim portion is an effective out and back there are only 3 buoy turns which eliminates navigation concerns as well as issues with swimming on top of others.

The swim entrance starts on the sand and finishes on a (slippery) boat ramp but also makes it a good entrance and exit spot for spectators. The lack of sand at the exit makes T1 easier, although there is still a 150 yard run up the parking lot and into the transition.

map of oc tri swim course

While the rest of the course is hard to watch, the finish line is back in the same location as the swim start and exit and the beach, park, and snack stand make it a great place for families or friends to hang out while athletes take on the bike and run courses. If you have spectators coming let them plan to hangout here during your race, it’s a nice spot especially once the sun is out.

OC Tri Bike Course

Biking on the OC Tri course is a lesson is not quite flat but not quite hilly. The course starts off on a slight uphill out of the transition and organizers are always nearby warning folks not to clip into their pedals before checking their gear. Someone falls each year doing this as they underestimate the grade, put your bike into a low gear in the transition area and you’ll be fine. There are a few 90 degree turns right away, then another a mile in, but form there there are no more hairpin turns till the halfway point. After leaving the lake area the course quickly heads out of the city and onto a popular weekend riding and motorcycle route through Santiago Canyon.

It is a beautiful ride that is dotted with green during the late Spring, although the rest of the year it can be a very hot and dry ride. The out and back course starts with a decent hill, picking up around 500 feet or the total 1700 vertical feet in the first few miles. From there it rolls mostly downhill out to the turn around. The turn does a loop over itself using a state park bridge, so there is no 180 degree turn although there are some tighter turns that break up a good pace. These also allow the course to be open and reduce the risk of getting caught in traffic since the course stays open to cars throughout (although some local officers are near major intersections).

OC triathlon bike course profile

This middle portion of the course, from around mile 5 through 21, is perfect for getting into an aero position. The climbs come at your gradually so getting into the right gear is fine, and putting your head down and churning out some watts is entirely possible.

On the return you pick up a more gradual incline over a good distance and then finish on a strong downhill that jumps onto a bike path. The bump from road to bike path is one spot to keep in mind as the lip from the road to the path is non-trivial and it is worth taking it more head on than the natural tangents of the course would suggest.

The final mile on the path also provides a good opportunity to ease back as there are some downhill spots where carrying speed as the path winds is plenty fast, especially since there are bound to be a handful of local riders and walkers on the path since it is not closed for the race. This portion of the course is a good idea to NOT be on aero bars as the bike path is a prime spot to have to hit the brakes quickly as potential obstacles pop up.

OC Tri 10k Run Course

Running the final 10k also can be misleading, it really should be though of as 2 separate 5ks.

Out of transition 2, which is no where near transition one and the swim course, you start on a gradual downslope for the first 2.5 miles. Dropping over 200 feet over 2.5 miles is great if you didn’t burn your legs on the bike, and is fine even if you did since it’s not so steep to hurt but enough to help move quickly. This is the first of the two 5ks and eases the pain and awkwardness of running off the bike.

From there the course changes drastically for the second 5k, turning left up through a dirt path and jumping onto a mulched trail for a steep .2mile with +100 feet of climbing. From there the flattens evens out along a creek bed path, but generally winds around and is not uniformly flat but at least avoids sustains hills. Midway through there is another steep climb along a sidewalk through a neighborhood, then back to a paved trail at the peak. The rolls to the finish wind up on a major street where you can open up a stride. The final half mile of downhill into the Lake Association parking lot serving as last boost to the self esteem, and can lead to plenty of finish line races with nearby competitors.

orange county triathlon run profile
OC Tri Run Course Profile

At the finish there is a short chute right beside the lake. Spectators are bunched up here by the snack stand and lobby and are a friendly face after most of the course is unseen by friends and family. Once finished the 70-75 degree lake water makes for the perfect place to cool off and catch your breath while eating a snack as well.

Dealing With Separated Transitions In A Triathlon

Despite being a small event (400 people) with great organizers, the OC Tri does pose one logistical issue. The two transition areas of the OC Tri are not in the same place. The swim-to-bike transition (T1) is about 1.5 miles from the bike-to-run (T2) transition. This requires an added layer of setup the day prior if you need anything at T2.

Since most athletes at the Olympic distance have dedicated bike shoes vs. run shoes many will have to have both setups. Both transitions are large enough that finding an open spot is not much of an issue. The biggest thing to remember is that you may want to over stock any specific nutrition you need in each area.

Towels at T2! Having a towel is common for a swim to bike transitions, but in this case although you start on sand the transition out of the swim in not through sand. On the flip side, T2 is in a dusty field, so if you only have one towel to dedicate to a transition area there is a good argument to be made for choosing T2.

Is An Olympic Distance Triathlon Good For A First Triathlon

Is OC Tri a good first triathlon? YES! The event is small and well organize so you will be able to navigate most of the logistics. The swim course is great for a beginner as it is not a mass start, and avoids any issues with swimming in a current. If you are in shape to do a full Olympic distance triathlon than there are only a handful of others in the area to consider. Even if you are not from the area, Mission Viejo is a near lock for great weather, and is close to tons of other great attractions in Southern California which makes it a viable option as a destination event.

Lake Mission Viejo Water Temperatures

When preparing for a new swim a big concern is what the water is going to be like. While you do not need a surf report, since the swim is in a lake, you still may be curious what the water temperatures are like. Anecdotally we have NEVER had a wetsuit during the OC triathlon swim in Lake Mission Viejo and it is not uncommon to see a number of others at the start line without them. A wetsuit will help with flotation and many argue will result in a faster swim, but it is far from a necessity for the race.

Live weather at the lake is available at their website, although annoyingly the water temperature readings are rarely populated. The post by the Lake Mission Viejo Association also suggest that for a Late April – Early May event the historical temperatures are fairly narrowly in a 65-70 deg window. Wetsuits are still allowed, and were even in later seasons, but are not required.