I grew up hiking/backpacking and camping so, post-surgery, it became important for me to overcome my fear of getting back out into nature. Like you, I was anxious at first. I've since realized outdoor activities with an ostomy is actually easier than without. As of today, my ileostomy and I have backpacked over 280 miles on the Appalachian Trail and countless miles on other trails around the East Coast of the US. While camping in the backwoods, many backpackers use "wag-bags" to pack-out waste. It's part of leave no trace. This method works amazingly well for ostomates since we empty from the front. We can also utilize cat holes if permitted in the area we're backpacking. I must admit hiking with meetup groups can be challenging since ileostomates are on different bathroom breaks than other people. i.e.-We usually have to empty soon after eating a snack. I will usually eat light while out with others who are not aware of my condition.
I also sail here in Annapolis. I usually just don't eat much until after the outing and may use a tablet or two of loperamide to slow output. I've also used wagbags on the boat and have a porta-potty onboard and will sometimes use a large plastic container if I'm solo at the helm.
Also, keep hydration in mind. I'm always conscious of water sources, electrolyte powders and salt. And a good barrier strip, supplemental adhesive, and/or tape makes sure my appliance stays in place. Get out there!