(In case you missed them, read part 1, part 2, and part 3.)

If you get hooked on stargazing, you’ll want to see more. You might get to the point where you’re willing to spend a little cash to accomplish this. You want to optimize the utility and value of any astronomy gear you take cruising, and so far, that’s been easy: the binoculars serve a valuable marine/terrestrial role aboard, and none of the other items cost much or take up much space.

That’s about to change, so you’ll want to give this some thought. Due to space constraints aboard a boat (any boat!), we almost never carry any accessory that only serves one purpose. We also avoid bulky gear, and gear that is fragile or easily damaged by moisture. Where does that leave us? In my opinion, the first item to consider is a tripod, and the second is a telescope.

While ashore (or aboard, I suppose, if your boat is extremely still), you’ll appreciate a tripod with a sturdy binocular mount. While you can see a lot just holding those 7×50s up to your eyes, you can see even more if they’re not wobbling around. Even while holding them, just using some stable object such as a monopod, tree, or a picnic table to steady them can reveal, for instance, the four “Galilean moons” of Jupiter. Mount them on a tripod, though, and you’ll have no doubt about what you’re seeing. The Galilean moons will be obvious. The Plaeidies star cluster will resolve into more than 20 individual stars, not just the seven or so you can see with the naked eye.

I use a photographic tripod from Bogen-Manfrotto (model 3401B), with a fluid-motion video head on top (model 3130). This is pretty stable for a pair of 7×50 binoculars, and the fluid head allows you to pan and tilt smoothly, which is important when you’re navigating from one astronomical target to another. It also makes spotting ships, birds, and aircraft a lot more fun, since you can track moving objects and keep them in view. You can’t do that with the typical still-camera mount on most photography tripods; the fluid motion is critical.

If you really get into it, you might consider…a telescope! You can learn more than you’ll ever want to know about amateur astronomy by browsing the forums at Cloudy Nights. I encourage you to spend some time over there, if you’re at all interested in astronomy.

But here’s my heartfelt advice: for cruising, get a high-end “terrestrial” spotting scope, not an astronomy scope. The brand names you’ll consistently find at the top of the heap are Leica, Swarovski, and Zeiss. This isn’t to say that other manufactors, including Nikon, Kowa, and Fujinon, don’t make great spotting scopes, by any means.

I own an 85mm Zeiss Diascope with the variable-magnification eyepiece, and it’s absolutely wonderful. Spotting scopes, designed primarily for bird-watchers, are lightweight, compact, durable, and waterproof; precisely the features we look for in cruising gear. Also, they display an erect image, not an upside-down and reversed image as dedicated astronomy scopes do. For myself, I want a telescope I can use for informal astronomical work AND for terrestrial spotting. The erecting prism degrades the image a little, which is why astronomy purists will steer you away from them. Ignore that advice, for the time being. If you jump into astronomy with both feet, you’ll form your own opinions about what you want anyway.

To be fair, my little spotting scope does not produce the expansive, full-color views you see on the cover of National Geographic magazine! To give you an idea what you might see through a top-quality spotting scope, here’s an image of Jupiter that is very similar to views I see through my Zeiss from light-polluted Seattle skies.

As in this image, I see a disc, not merely a point of light. The disc has two major dark bands across it, corresponding more or less to the latitude of our own tropic lines on Earth. Saturn resolves as a ringed disk, but no color variations are visible on the face of the planet or the rings.

I only own two telescopes: The Zeiss and a nine-inch Dobsonian reflector, which is about four feet long. All things being equal, a bigger telescope is better. Views of Saturn through my big telescope are very slightly better than with the Zeiss: I can see the Cassini Division in Saturn’s rings, for instance, and slight variations in the surface of Mars. However, the fact is that I almost never use the bigger telescope: I find it cumbersome to haul outside, I don’t enjoy fiddling with the eyepieces, and it’s much more difficult for my children to use. The Zeiss is dead simple; adjust the tripod to a good height, point the telescope where you want it by sighting along the tube, look through it on lowest magnification and find your target, and adjust zoom and focus until you’re seeing as much as you can. Remember, “the best telescope is the one you have with you!” As with my Fujinon binoculars, this is a scope I can take with me.

I use the same tripod with both my binoculars and my spotting scope, but for astronomical use, I change to a Manfrotto 410 geared head, which allows for very fine adjustments in three axes. I’ll be honest: this tripod, even with the geared head, is just barely adequate for the spotting scope. It’s a bit wobbly at 20x magnification, and you really can’t touch the tripod or telescope at all when zoomed in at 60x. Get it pointed in the right direction, remove your hand, make a focus adjustment, remove your hand, re-center the image (which is drifting out of view as the earth rotates), remove your hand, etc. This photographic tripod is the weak link in my portable astronomy kit, right now. If I were to spend more on astronomy gear, my next purchase would be a dedicated astronomy tripod with a motorized equatorial mount that keeps the telescope pointed in the same direction while the earth rotates beneath it.

In case it isn’t obvious, I’ll point out that a spotting scope with 20x-60x magnification is essentially useless aboard the boat; There’s just no way to hold it steady. Hold on…I may be wrong about not being able to use a spotting scope aboard a small boat. I’ll have to do some more research on this.

Hopefully, I’ve given you some helpful information and realistic expectations about the sort of views you can expect to see with the sort of equipment you might reasonably carry aboard a cruising boat. Dedicated amateur astronomers may scoff…this discussion of “advanced gear” is really pretty basic. Hey, if you want more, head over to Cloudy Nights. I’ll remind those readers that I’m writing for a crowd that, like myself, might best be described as “incidental astronomers”: We’re not out there to do astronomy, we’re out there to go cruising on our boats. Once in a while, we’ll glance up and realize that it’s a lovely, still, clear night, and we’ll go grab the binoculars and have a look. For us, a heavy tripod and a spotting scope are pretty specialized bits of gear to bring along!

Good luck with your astronomical adventures. In case you haven’t watched The Thing recently, I’ll leave you with this…

“Watch the skies, everywhere! Keep looking. Keep watching the skies!”