Thank you for your interesting question. I can't recommend Hearphones for use while kayaking. You might be fine hiking with a hat, or biking if your ears are protected from the rain.
Here's an excerpt from the Bose Hearphones Owners Guide.
'"Do NOT submerge or expose the headphones for extended period to water, or wear while participating in water sports, e.g., swimming, waterskiing, surfing, etc."
Thanks for the suggestion. While I can't comment on things that may or may not be in production, we are listening.
How are you enjoying your Hearphones?