Rudely awoken by an explosion!

Sunday 6 Feb, Mexico day 17, El Cid Marina: Violent wake up alarm. Get rental car and day trip to Puerto Aventuras.

At 05:40 we are sharply woken up by a violent explosion followed by a deafening noise. To describe the sound, my first thought was the Volvo or generator was running at full throttle with broken metal parts graunching inside. Then, when I quickly realized that was not possible, I thought a boat must have hit us at full speed and the graunching sound was our hull being ripped apart. So, my first instinct was to rush to the cockpit to see the carnage.
But as I dashed passed the engine room door, the sound was clearly from within. WTF could possibly be happening in there?!!!
I gingerly opened the engine room door, fully expecting to be greeted by fire and smoke. I wasn’t totally wrong. No flames, but dense “smoke” immediately billowed out the gap in the door. Then the realization came, it wasn’t smoke, it was steam. And although I could not see through it, I immediately guessed what was happening, and at the same moment I knew exactly which Numpty Captain was to blame. Yes, that would be me!

A few blogs ago, following me removing and electrically by-passing a faulty thermostat on the water heater, I had declared that I, Glen the responsible Captain, would now act as the thermostat, manually turning on and off the water heater as needed. This strategy worked fine when we were at anchor, because we can only have 220vac to heat the water when the generator is running. And given we only run the generator for a maximum of 2 hours at any one time, the water heater is never active long enough to overheat the water.
But now that we are in the marina and plugged into 220v shore power, it’s a whole different story. Last evening, I had switched-on the breaker for the water heater fully meaning to turn it off again in 1 to 2 hours. Well, of course, I should have known my memory better than that. I forgot to turn it off. And we now know it takes roughly 12 hours for the heater to boil the water, turning the tank into a bomb waiting to explode.

Although the violent noise made it sound like the tank itself had exploded, it was actually only the safety valve venting. (Thank god for safety valves!). But even then, with the valve only opening above 6 bar pressure, the steam and slugs of super-heated water venting through a ½” pipe (12mm) at over 100Psi makes one hell of a wake-up alarm!

My first move is to turn off the breaker for the heater and the domestic water pump. The latter of which was continuing to feed the tank with cold water. And even then, the venting continued unabated. It wasn’t until Oana also opened the hot tap in the kitchen and bathroom that the pressure and noise started to decline, eventually resetting the safety valve back to its closed position. By that time, the engine room, galley and aft cabin were full of steam, with all surfaces running with condensation.

The whole event left us both physically shaking with shock. We then remembered Emma and went to look at the effect it had had on her, fully expecting to see her cowering in a corner shaking with fear. But there she was, still asleep like an angel, and snoring! How could that even be possible? We chuckle to each other. We then wanted to go back to sleep ourselves, but by now we are fully awake and totally wired! So while Oana makes a calming cup-of-tea, I delve into fixing the situation.
With the water back on it takes a while to refill the tank. All the water must have blasted out in steam. But once full, I gingerly watch the domestic water system pressure start to rise, then stop at its usual 3bar. And I stare at it, sure there will be a drop off indicating a leak. But miraculously it doesn’t drop. The cold water side was protected from the pressure by the one-way valve on the tank’s plumbing. But the hot water side had been subject to 6 bar and I’m surprised none of the plumbing has failed. It turns out the only damage is to the bathroom tap where we had vented the steam. Its flow is now very low. Likely the steam has damaged the seals.

By breakfast time we are back to all water systems working as normal. And even now, several days later, I find it hard to believe such a noise did not yielded collateral consequences. Even so, it’s certainly an event not to be repeated! Lesson learned. A timer with alarm will be set each and every time we turn on the emersion heater from now on.
Oh, and when Emma woke up, unless we had told her of our drama, she would have been none the wiser. Maybe we should not have told her and just let her read it in the blog several days later!

At 10am our hire car is delivered directly to the marina. $55 per day. Very reasonable considering we paid more than this to rent a beaten-up golf cart for just 6 hours on Isla Mujeres. Again, there are tourist rates and there are the real rates.
We then drive off in the rain, south to Puerto Aventuras. This is where there is another marina which is housed inside a gated community. The drive is just over one hour, mostly along a good coastal highway. As we pass by Playa del Carmen we look down from the fly-over onto what looks like a pretty shabby town. A different image to what we expected of this tourist town. But we plan to visit it in more detail another day. And also when we catch the ferry from there for our planned day-trip to Cozumel.

Puerto Aventuras community is an interesting development. Almost 100% filled with expat-owner condos around dug-out waterways, a-la Florida style. But unlike Florida, it’s all very 1980s and becoming quite shabby in appearance. The marina isn’t really a marina as such, it’s just a high concrete wall in the main waterway, which you tie up to. That said, it is very well protected from the sea and wind. And apparently also very cheap. One fixed price for any boat (~$30) hence it attracts, and is full of, cruising catamarans.

We wander around in the drizzle, watching the playful dolphins and lazy seals in their enclosures, and when the rain becomes too heavy we stop for a meal in one of the many waterside restaurants and also a superb gelato. And we ponder why is it that Mexico has such great ice cream and USA doesn’t. At least, none that we ever found.
After a couple of hours stretching our legs, we head back up the coast to our marina. And given the rain continues, we settle in for a cinema evening. Starting to watch the series Yellowstone.

We have the rental car for a week, so in the coming days we will tick off all the sites we wanted to see. A nice bit of land tourism for a change.