This video provides a pretty good primer on costs and trade-offs of the different options:
Even though I have 2 drysuits, I almost always prefer wearing an appropriate wetsuit (I have 5 different wetsuits for a range of water temps) because I am a mainly a surf paddler/waveskier, or white water kayaker. Wetsuits work better for me. But, whatever your choice, you should wear something that provides adequate protection for immersion in the specific water temps, allowing for the "time window’ you need to conduct a self or assisted rescues.
I like your way of saying it - time window to conduct a rescue.
I find this is too often simplified to dress for immersion, making it sound like one should be dressed so they could spend days in the water. In most conditions, that person would be very uncomfortable when not in the water.
A lot of people have unrealistic expectations in terms of the time from when the USCG receives a distress call to when they arrive on scene. The USCG Search & Rescue units are expected to launch within 30 minutes and be on scene within 2 hours anywhere within their operational
area.
It’s not like calling your local fire department. Assuming you have the means of contacting the USCG or a local emergency dispatch service you could be waiting a long time for rescue even if they locate you right away. Although it can be faster, a kayak or a person in the water can be hard to spot, even if they know you position.
A nearby boat that is monitoring VHF 16, as they should be if they have a radio, is more likely to arrive first.
Solo paddling in open water has its risks. I have often paddled solo and I consider a VHF radio second only to a PFD as essential safety equipment in open water. If not just for yourself, it may come in handy to help someone else on the water.
