The Okanagan valley region of British Columbia is famous for it’s fruit and wine orchards, famous as the warmest place in western Canada, and famous as a lake vacation destination for power boaters of all types.

What the Okanagan is not particularly known for is a paddling destination, but with a 100km long lake that stretches from just past Vernon in the north to Penticton in the south, campsites scattered along the shores, great local fruit and vegetables, fantastic local wine, and generally warm weather we decided that it would make a really good five-day kayak trip.

Tuesday, July 16: Vernon to Fintry

We are up at 6:30 in Vernon to have breakfast, load the two Honda Elements, get all the gear down to Kin beach and unload in time to return the cars to mom’s house and have neighbor Jim take Kai and me back to the beach. The lake water in the morning is beautifully calm, and while the morning sky is mostly clear, cumulus clouds are growing all around us as the day heats up.

The first stretch of paddling, south-west from Vernon, is easy on the calm water, and is a perfect way for us all to get used to our boats again. We cross the lake easily to the west shore, then head south to Fintry Provincial Park, which was the site of a self-sufficient community of European settlers in the early 1900’s and is now a protected park and RV campsite.

We get to the Fintry campsite early in the afternoon under mostly sunny skies, and wander around for bit looking for our campsite. Everybody else has driven to this campsite, and we are the only ones to show up by boat. Funny, that. After setting up camp it’s time for a swim in the lake, and then we decide to practice kayak rescue techniques; wet exits and T-rescues. We are impressed that Marc is able to roll his ocean kayak!

The storms clouds that have been growing all morning hang on to their rain until very late afternoon, and only a few drops of rain hit the ground after dinner. As the evening cools, the clouds slowly dissipate and the stars are just poking out as we pack it in for the night.

Wednesday: Fintry to Bear Creek

The forecast this morning is for rain followed by wind, neither of which is fun but wind is worse since it kicks up waves. Trying to get on the water as soon as possible, we quickly wolf down breakfast, pack up camp and stuff the gear into waterproof bags, move everything down to the beach, and load it all into the boats.

Boats are in the water by 8:30 with the rain coming down lightly but steadily. Paddling in the rain is not at all unpleasant, since you’re usually wearing a waterproof jacket anyway, and as we leave camp the water is beautifully still and the air is calm and rich with moisture.  We are paddling about six km/h on the smooth water, with slight swells coming from the north helping to push us along. The water surface is only disturbed by the wake coming off our boats and raindrops, as we dip the paddle into the water on the right, pull, dip it in on the left, pull, and repeat. Very relaxing. We take advantage of the calm water and easy conditions to cover as much ground as possible before the expected wind picks up and makes the travel more difficult.

Two hours later, the rain stops and as predicted, the wind picks up and the surface of the lake develops small choppy waves, which soon become bigger ones, just starting to develop whitecaps, with a moderate wind blowing straight into our faces as we head south. Fortunately the west shore of Okanagan lake, north of Kelowna, is a series of small bays and rocky points, each a kilometer or two apart, and we are able to take small breaks from the effort of paddling into the wind and waves by sheltering in the lee side of each rocky point.

We get to Bear Creek provincial park after five and half hours of paddling covering 26km today, with an average speed of 4.7 km/h. We are all pretty happy to get off the lake, setup camp, and have dinner, which is an excellent Japanese soup of mixed vegetables, including lots of sea weed, plus salmon, prepared by Kai and Elke, followed by rice crispy dessert.

Wildlife sightings today included a few bald eagles perched on tall trees along the shore, as well as a blue heron.

Thursday: Kelowna crossing

We are up at 6am after a restless night where the wind was blowing constantly, shaking the big trees at the campsite. During breakfast the wind blows strongly, then calms down, then blows strong again, and the sky is full of broken clouds. We had really been hoping for calm winds this morning to make the 2.5km crossing from the west to east shore but it’s not looking good.

As we pack up camp and load the boats the wind is coming straight down the lake from the north. The shortest crossing to Kelowna is to head south-east from the campsite, nearly perpendicular to the wind, and parallel to the waves. However, traveling parallel to the waves is difficult and dangerous in a kayak because the boats are very unstable when pushed from the side. We can see some whitecaps in the middle of the lake, and discuss options and strategy for crossing in the wind and waves, including the possibility of waiting a day.  In the end we decide to go for it, turning the boats up or down wind once we enter the big waves.

Soon after launching from the sheltered beach we are into open water with small choppy waves, 20-30cm high, which are not too bad. The waves rapidly get larger as we move away from the protected shore, where the north wind has had 25km of lake to really stir up the water. My portable kayak has no rudder, and without it I am unable to turn the boat up-wind, to the left. Running parallel to the waves is rapidly becoming scary, and the only real way for me to get to the opposite shore is to run the boat 30-45 degrees down-wind from the waves. This allows the boat to surf across each approaching wave and gain some speed before climbing up the back of the next wave.

No tipping the boat and no photos!

The other boats, Elke and Kai in their double, and Marc in his single kayak, are able to travel upwind, or straight across, but without a rudder I can’t go in that direction, so I’m on my own now in waves that are at least 1m high, and I’m totally focused on stabilizing the boat and managing each approaching wave. The boat is working well and I’m really moving fast, but each incoming wave tries to turn the boat to the right, out into the middle of the lake, and so I’m paddling flat-out to keep the boat moving at 30 or so degrees to the waves, and not tipping over!

It’s said that time flies when you’re having fun, so apparently there was no fun in getting across the middle of this lake as I seemed to be stuck in the big waves for an eternity of intense focus, hard breathing, paddling at 100%, balancing the boat and managing each wave.

In reality it was probably 1/2 hour before escaping the big waves and approaching the west shore where I can relax a bit. I had lost sight of the other boats upon entering the big waves and am just starting to look around again for them when suddenly I hear Marc, Kai and Elke behind me; what a relief to be back together again and safe after that intense crossing!

We touch paddles in celebration and then head south along the shore towards the center of Kelowna, which unfortunately involves going around a large log boom that forces us back out into substantial waves. The waves are coming from the north (behind us) and reflecting off the log barrier to our left, causing a chaotic jumble of water that tosses us in all directions and makes for difficult, unstable paddling.

After getting around the logs we make a bee line for the first beach to take a break and shelter from the wind and now rain. It’s not warm on the beach, but at least it’s safe and dry and the world is not rocking madly back and forth. Phew.

On difficult days like today it helps to set short, achievable goals, and our next mini goal is to get under the highway 97 road bridge across Okanagan lake at Kelowna. Passing under the bridge turns out to be easy, and the south side of the bridge is sheltered from the north winds, so the water is calm, and we finally have some easy paddling conditions. There is one large bay to cross before continuing south along the east shore, and with the winds calm down now and the sun coming out, we decide to save some time and energy by heading across the bay rather than following the shore. Unfortunately a thunderstorm coming from the west catches up to us halfway across the bay and we are pelted with rain and hail before reaching the shore and finding some shelter under the trees. It appears that the weather is not done with us yet.

After this latest storm we work our way south along the east shore through half meter waves which are mostly going in the direction we want, then take a break at a regional park for lunch.

After finding some shelter from the wind and warming up in the sun, plus using hot air dryers in the washroom, we continue south along the shore towards our campsite at Okanagan Mountain provincial park. It’s such a relief to finally makie it to camp after an intense day of storms, wind, rain, hail and big waves! We take our time setting up camp, under the watchful eyes of a both a mature and a young bald eagle, then prepare dinner while two families of Canada geese come ashore and eat their own dinner. Dinner for humans is Thai curry with vegetables and Ovaeasy powdered eggs over rice noodles, followed by sitting around a campfire watching swallows fly acrobatic maneuvers over the water chasing bugs. Very peaceful!

Our campsite is on a small point of land sticking out about 50m into the lake, and falling asleep with the sound of water on three sides is a little spooky. As I drift off to sleep I feel the memory of water rocking me back and forth while listening to the waves gently splash against the shore a few meters away.

Friday

Today is a short day, and after a relaxed breakfast and packing up camp, we have only 10.5km to go on the lake. The weather in the morning is good, and it stays mostly nice all day, with just a bit of wind and a light sprinkle of rain coming in late morning.

So nice to have an easy day after the intensity and exhaustion of yesterday! We’ve been working our way slowly down the east side of the lake, and soon get to our new camp location, tucked into a beautiful little cove on the south side of the park just around blustery point, past Rattlesnake Island. A small, rocky beach with just enough space for three tents sits at the base of a hillside sparsely covered with big pine trees.

After setting up camp Kai and I go for a swim in the lake, which is much colder than it was two days ago, thanks to yesterday’s storms mixing up the warm surface water layer. Refreshing! Everybody else goes for a hike up the hillside in the afternoon but I’m quite happy just sitting in the sun writing up yesterday’s excitement, napping, and watching the birds swim by.

Dinner tonight by Elke and Kai is couscous with rum marinated chicken, from a can of course, with an Alfredo sauce. Another excellent camp meal!

Saturday

We wake up early with a bit of rain falling out of a completely overcast sky. With 25km of paddling to get to Penticton we have a long day today, so we eat a quick breakfast and start packing up. A lone duck is paddling just offshore, and is soon joined by it’s friend / partner / sibling (?) with a noisy quacking, honking and flapping of wings greeting and then they both paddle around just off shore searching for breakfast in the shallow water. The lake is very smooth early in the morning, but the first wind of the day picks up as we are packing the boats and ruffles the smooth water. It’s blowing from the north, which will work in our favor as we head south to Penticton.

As soon as we leave the protection of the cove we are into the small waves, which are already big enough to surf and so push us along nicely. Not much photography on the water today as we are all just having a great time paddling in the fun waves and enjoying the acceleration and speed as a passing wave picks up the boat and you surge forward, surfing down the front side.

Science break: wave packets

We notice that the waves today come in groups of about six, starting small, building to a few big ones, then tapering off to smaller waves at the end of the group.  Then there’s a pause of maybe 20 seconds before the next group of waves comes along.  This makes for great surfing, as you can feel the tail of the boat lift with the first wave in the group, immediately start to paddle harder to speed up the boat, accelerating with each wave that pushes the boat forward. In between wave crests there is time for a quick rest as each wave overtakes the boat and the tail of the boat drops into the trough, then accelerating again with the next wave.

Super fun wave surfing! But what causes the waves to form into groups of six (or so)?

Waves on any large body of water (lakes or oceans) are formed by the interaction of wind and gravity on the water. The wind blows across the surface, pushing on and disturbing the water, which then rebounds from gravity. This initially creates ripples and small waves, but as the wind blows for a longer time (and distance) the small waves merge, and the continuous input of wind energy forms ever larger waves.

The wave height (crest to trough) and wavelength (crest to crest) are determined by the wind speed and distance the wind blows across the water, called fetch.

In general, the velocity of a surface wave on a lake depends on both its wavelength and the water depth, but in deep water, the wave velocity depends only on the wavelength:

\(C = \sqrt{\frac{gL}{2\pi}}\), where g is the gravitational acceleration (\(9.81m/s^2\)) and L is the wavelength.

The period of the wave (time between crests) is simply \(T=L/C\), where C is the wave velocity. Because water wave velocity varies with wavelength (or period), water waves are dispersive.  A dispersive wave changes shape over time, as its various components go running off at different speeds. Because the wind does not blow steadily, typical waves on a lake have a variety of wavelengths and therefore velocities, with longer wavelengths traveling faster than shorter wavelengths.

Wavelength L (meters)	4 m	8 m	12 m	16 m
Wave period T (seconds)	1.6 s	2.3 s	2.8 s	3.2 s
Deep water wave speed C (m/s)	2.5 m/s	3.5 m/s	4.3 m/s	5.0 m/s

Another basic wave phenomenon is interference; two crests add to create a taller wave, while a crest and trough cancel to form a small wave. When the waves have different velocities and wavelengths, this wave interference tends to form bundles of waves called wave packets.

This video shows how two single-frequency waves (red and blue) interfere to form wave packets (black, at the bottom).  The wave packets can travel at a different speed (called group velocity) than the speed of the individual waves (called phase velocity).

Note that in this case, the resulting wave packets move at a higher (group) velocity than the wave crests (phase velocity), which move at the average speed of the red and blue waves.

And that’s the answer to our question! The groups of surfing waves are called wave packets, and form when waves with different wavelengths and velocities interfere with each other.

Penticton arrival

Thanks to the steady north wind and the resulting 50cm waves we make 25km in only 4 hours today.  The hours pass quickly as we head south along the shore, surfing the waves packets, resting in between, waiting for the next packet to arrive, and repeating. So fun! The sun is out, the sky is blue, this is the paddling trip we were hoping for!

Soon, Penticton beach appears and and we surf the boats into the sand. Most conveniently, not far from the beach in Penticton is the excellent Cannery Brewing company, so naturally after getting ashore and unloading the boats and gear that’s where we end up.  An excellent end to a great little Okanagan adventure!

– Darren Foltinek, 2019