Vasa Swim Ergometer
Having used a friend's Vasa, I'd always wanted one, but the Catalyst for getting one was cancer, and two 5-hr brain surgeries, which created a mild short-term seizure risk (luckily, no seizures). Nobody has drowned in their basement after a seizure-induced fall off their Vasa Swim-Ergometer.
If you're considering buying a Vasa, talk to Doug for a specific discount-code.
I went with the Vasa Swim Ergometer ANT+, (as opposed to several other products) which allows me to wireless upload my swim data to sites like Strava, while still lying on the bench.
I love the trainer, and now have full Triathlon Training Capability in my basement, which also has a Wahoo Kickr, a Landice L8, and a Bowflex.
Here's the data from my first trial swim on the bench, data was collected and uploaded on a Samsung S4 (which has ANT+, so no dongle required) using the Wahoo Fitness App.