This easy-to-miss Marriott site earned me 3,000 bonus points

There are the big and mostly obvious ways to earn points and miles — such as through credit card bonuses and spending, and, of course, on actual travel. But there are plenty of other easy-to-miss ways to earn rewards, too.From dining programs to Lyft rides, Starbucks reloads and so much more, you can earn points and miles in places you might not expect.And recently, for me, one of those places was on a private boat excursion in the middle of a bioluminescent bay during a trip to Grand Cayman.Taking good photos of the bioluminescent bay in the dark turned out to be ... impossible. But earning a few thousand Marriott Bonvoy points on the boat ride was shockingly easy.You can't see the people well, but you can see how cool the bio bay was. SUMMER HULL/THE POINTS GUYHere's how I did it: Marriott has what it calls a Marriott Tours and Activities site where you can book excursions around the world and earn, or even use, Marriott points in the process.Marriott doesn't operate these attractions and tours itself; instead, it serves as a third-party broker or aggregator. Some of the types of activities I've seen available to book through the site include:Snorkeling tripsWalking toursBoat and...