Life at seventeen degrees latitude can be hot. Not just go to the beach and sip on a fancy drink hot. It’s stinking, sweaty, sun scorched, burn your feet on the beach sand hot. So hot that you begin to question your choice to spend time at such a low latitude. Needless to say, being comfortable while living here on a boat takes some creativity. But never fear. Many generations of tropical dwellers have come before you and perfected the art of living under the powerful sun.
On land or while stuck in an airless marina waiting out weather, the obvious solution is air conditioning. I’m the first to admit that when the boat is docked in a stifling-baking-dead-air-zone of a marina for hurricane season, we stick an air conditioner window unit in a hatch just like everyone else.
But beyond summer marina life, depending on a buzzing air conditioner detracts so much from the boating lifestyle. The generator required to run it at anchor is loud, electricity on the docks is expensive, and boats are not designed to be lived on with the windows all shut up.
Boats are all about combining the indoor and the out in your home. The luxury of a comfortable living area mixed with gentle ocean breezes, the sounds of fish and seabirds splashing in the bay, the wafting salt scent of the ocean. If you give that all up you may as well move into a condo tower on shore.
Half Moon in particularly well set up to blend the indoors with the out. We have a huge opening door between the salon and cockpit, two giant forward facing windows in the salon, six top opening hatches and two opening ports in the hulls. Close all that up and spending time on the boat starts to lose it’s appeal.
The solution is a dynamic one two punch that people living in hot climates figured out many generations ago. Both solutions are passive, requiring no pumps, compressors, electricity, or emergency repair bills. The solution requires some upfront thought and effort, then rewards you handsomely for as long as you let it ride. What is this magic duo that turns life in the blistering tropics from miserable to pleasant? Drumroll please…..
Shade and air flow. Air flow and shade. Simple, cheap, effective. Step into any Mexican home or business lacking air con (the majority) and you’ll immediately notice how much cooler it is indoors than out. Buildings are built of heavy masonry walls and feature big windows and doors that are left wide open to let the breezes waft through.
Those who can afford it use tile or masonry roofs as well. Overhangs and porches grace the structures of those lucky enough to have the cash to buy the materials to add them on. Those who don’t strategically hang woven palm draperies, tarps, or sheets near the windows to block the sun but still allow the wind to flow. The overall effect is a comfortably cool, airy structure with enough thermal mass to absorb the sun’s radiation all day without heating the interior. No air conditioner required.
Not directly related to the dynamic duo of shade and air flow, but also important is scheduling your day according the sun. The typical workday starts early during the cool morning hours. People work till lunch around one or two pm, then rest during the hot afternoon. Most return to work from four till seven before calling the day over.
The fishing fleet in Zihuatanejo goes one step further. Dozens of fishing panga’s sit on the beach abandoned in the heat of the day. Around sunset the beach comes to life as crews of fishermen load their boats and drag them down to the water. By the time the sun is fully set most of the boats are gone to sea. Near sunrise the process reverses. The panga’s stream back into the bay, run up on the beach, and a fish market springs up at the tree line behind the sand.
The fishermen lay their catch out on tarps and blankets while early morning customers peruse the nights catch. By nine am the fish are sold, the boats are stowed safely on the beach, and the fishermen are heading home.
While we don’t go so far as to emulate the fishermen and only work at night, we do match our schedules according to the patterns of the sun. Outdoor boat work is relegated as much as possible to the early morning hours. As the sun heads towards noon and turns the deck into a baking wasteland we head inside. Around sunset we peek back outside with cocktails in hand to watch the sun fade.
To create a comfortable interior during the day on a boat you can’t directly copy the Mexican technique of surrounding yourself with heavy masonry walls. Most boats of cruising size simply don’t have the displacement to handle the weight. Not to mention block walls on deck would look weird and make you sail slow.
What you do have going for you on board a boat at anchor is lots of surface area that can be shaded and a reasonably reliable breeze courtesy of the ocean. With these two elements you can create a surprisingly comfortable home on the water no matter how hard the sun tries to reach you.
On Half Moon we had a lot of surface and many large windows to tackle to get the boat comfortable. Most monohulls will have a simpler set up process, because their deck space and windows are smaller, but the techniques are the same.
In our case the first step was to apply direct shade on the outside our big salon windows. The windows are already heavily tinted, which would be sufficient in a northern climate, but here the tint needs augmentation. We opted for a expensive but long lasting Perfetex brand mesh fabric that blocks about 90% of the UV rays. The cloth was cut to fit each panel of glass, trimmed out with Sunbrella brand fabric, and attached to the boat with super strong glue-on snap fittings. The difference between having the window covers on or off is apparent immediately. Without the covers sitting on the settee in the salon is uncomfortable. You can feel the heat radiating through the glass right away. With the covers on the radiative heat is cut by at least (subjectively) half and the settee becomes usable.
Up next was to cover the opening hatches in the deck. We have six large opening hatches installed like skylights in the deck, which make for for excellent air flow, but also allow copious amounts of sunlight in. The challenge here was to block most of the hot sunlight while still allowing the cooling breeze through the windows. The solution was to make covers that fit snugly over the opening part of the hatch. The covers are held in place with a low profile shock cord so the window can still be closed in case of rain or ocean spray.
Since we were losing the ability to see out the windows when closed anyways, I also cut the reflective windshield material commonly used for car windshields to shape and slipped the material under the cover. The covers with their inserts do a fantastic job of covering the plastic windows and reflecting the heat but still allowing the windows to function. Unrelated to blocking heat, but a nice bonus; covering this type of plastic window prevents the commonly seen sun damage known as crazing.
We have large fixed port lights on each hull. Since they are in the bedrooms and we rarely want to see out of them, I cut to fit reflective car windshield cover material and used clear double sided tape to attach the pieces to the inside of the windows. For aesthetics, those are covered with white pleated blinds. The port light covers let in a nice glow to keep the cabin from feeling gloomy, but block the bulk of the suns heat.
Last, but probably actually the most important part of the shade half of the dynamic duo is the big awning. To make the awning I used several rolls of material from Home Depot meant to make backyard shade awnings for gardens and pergolas. I sewed several big pieces together and fitted them around the mast, up to the forestay, and out to the lifelines.
This cover hangs high enough from the deck that from the cabin you have a clear view out, and allows a nice breeze to flow under it. Most importantly, it blocks about eighty percent of the suns rays. We take it down to go sailing or when the wind gets above twenty knots at anchor, and joke that when it’s back in place we’ve “turned on the air conditioner”
I did learn the hard way that this awning takes some abuse and needs to be stitched strong. It’s large, and winds at anchor can pipe up quickly, so it must be able to withstand a stiff breeze without tearing or ripping out it’s attachment points. If you have a cat like I do, she will probably also think the awning is a custom made cat hammock/playground so it needs to be strong enough to hold her weight as she bounds around on it.
After the original single stitched seams tore out, I triple stitched the hems and replaced the cheap-o grommets used in V1 with tie lines sewn directly to the awning for attaching it to the boat. I also learned it’s also well worth it to pony up a few extra bucks to get UV resistant thread instead of cheaper, more typical upholstery thread. Being in the sun all day kills normal thread in a couple of short months. Restitching miles of awning edge after just a couple months of use is a real buzzkill.
The second element of our dynamic duo is air flow. Often at anchor you’ll have a nice steady ocean breeze that can be directed through your living space. The flow part of air flow is critical here. Opening a window at the front or aft of the boat without opening a pair for it at the opposite end will just create a dead zone. Like the Mexican homes with doors and windows at each end of the home you’ll notice an immediate improvement when the air is able to enter and exit the boat uninterrupted.
To augment every last bit of breeze a wind scoop comes in handy. The wind scoop is a lightweight, half-round canvas device that sits on deck and funnels wind down into the cabin. It’s particularly useful on a traditionally built monohull with fewer and smaller windows than late model boats. On Half Moon we are fortunate to have enough windows that we don’t need a wind scoop, but boats with less ventilation will benefit greatly from one. Whoever thought this up is an absolute genius. It’s completely passive, maintenance free, and can make a slight breeze feel like a giant fan is blowing in the cabin.
On occasion, mother nature doesn’t cooperate and the natural breeze dies off completely. It’s usually at night when the land effects fade that this happens so is bearable, but luckily for us we live in a time of cheap solar panels and high capacity batteries so we can supplement the breeze with FANS! A good fan can mean the difference between a stuffy cabin and a pleasant refuge when the air is calm.
On land a fan is something that hangs from the ceiling to provide air flow and is taken for granted. A ceiling fan in a home is just another long lived appliance that is chosen for aesthetics and and functionality is taken for granted. On a boat not so much. Life is hard on small electronic devices in the cabin of a boat so the device must be built to a high standard. When looking for a fan, most boat owners search out a low power draw, hardwired, twelve volt fan of solid construction.
The low power draw and twelve volt requirements are to allow the fans to run off the boats house bank. If you have to turn on a generator or inverter to run the fan you may as well just give up on the benefits of boat life and install an air conditioner. Hardwired is important because this is your home. Having wires strung out around the cabin is ugly and unsafe in a seaway. Solid construction, self explanatory. The boat moves, sometimes violently, it can be humid, salty, damp, or if the day is really bad the cabin gets wet inside.
My personal favorite is the Caframo brand 757 fan. The fan draws next to no power, can run for days on end without overheating, and is built with quality materials so it lasts several years. As the person who does the cleaning onboard, I’m particularly partial to the 757 model because the rubber blades are exposed and easy to clean. This preference is by no means universal. Ask ten cruisers what they use and you’ll likely get ten different, very strong opinions on which is best.
As cruisers opinions are different, so are their shade and window adjusting techniques. Every boat is a special snowflake with different places to hang a shade, different window opening options, and residents with differing opinions of comfortable temperatures. I challenge you to look around your own home or boat. Is there anything you can do to bring the Mexican mindset into you home to make it a more pleasant place to live?