We like to try to get to Mexico once a year and this year we got lucky with a last minute trip booked at great rates. We stayed at the Grand Palladium Kentenah resort and would go back there again. We flew from Gatwick with Thompson who had a pretty good approach to dive gear and flew home with them to Manchester - yes the snow got us diverted 100s of miles from our car! Anyway, enough of that - the diving.

This was my fifth trip to Mexico and Al's fourth so we've done a fair amount of diving there. This made for some interesting discussions about where to dive.

Al and I choose to dive with Zero Gravity when we go to Mexico and, unlike most we hear, we opt for guiding. I'll talk a little more about that later. Zero Gravity make life easy, proving gas, entry, gear rental, gear sales where necessary and expertise. Gear is stored at the shop, lights charged there too so no need to lug gear back and forward to the hotel each day. It is supposed to be a holiday after all

So on day 1 we met Danny and had a chat. Our preference is one dive per day with enough gas for three or so hours in water. We ran through some options and Danny suggested that we go to Taj Mahal. We've done a fair few dives in Taj Mahal as it is next door to Zero Gravity and I thought we had done pretty much all of the cave we could - including getting out underground and crossing to another line on a mega 5 hour dive last trip. Danny grinned and said 'There's a lot more to do yet - come and see'

A large part of this dive would be through the halocline. A halocline is when less dense fresh water from the land forms a layer over salt water from the ocean. In caves you can get to dive where the two layers meet - which stirs them up. The first diver gets beautiful visibility. The guy at the back gets to see the dive as if through vaseline!

Started with just one stage. Headed off following cavern line. This was the opposite of what we'd done before. Once again the Mexican caves offer lots of possibilities - even at sites you think you've exhausted. A fair way in after a couple of Ts, Danny set a jump off to the left into some big chambers called the Chinese gardens - very pretty! Beautiful piece of flow stone that must have been 2 metres tall caught my eye. We went as far as we could go before sidemount territory turning the dive.

Back to the mainline and we picked up our stages using them for another 25 bar into the cave. We had to then drop them in a halocline section. We carried on in some very blue passage with very gnarly rock formations. We reached the end of the line seeing the waterfall. The hydrostatic pressure of fresh water entering is so strong it creates a rippling halocline at the ceiling which looks like a horizontal waterfall. We stayed for a couple of minutes before exiting.

Danny's light had been flashing on and off a bit on the last bit of the penetration. When we turned so that he was behind me I decided that I would not be able to stand that on the way out and asked him to move up into the middle of the team. It turned out to be a fault in the strain relief cord but it flashed all the way out. Good job it was an LED head or it would have blown. As it was I got the giggles as I watched 'Disco Danny' flashing all the way through the halocline on the way out. I could see very little whenever we were in the salt/fresh zone as I was now at the back of a team of three but I didn't really care

Day 2 we headed for my favourite cave in Mexico - Dos Pisos. Chris and Fred haven't dive here yet only Danny - so as it was our last day with Danny, if we wanted to go it had to be today. It didn't matter, Danny was bringing his toys with him and we got the best holiday mementos you can ask for - photographs!

You enter Dos Pisos through a low series of low restrictions - real belly crawls which were fun with stages - and even more fun for Danny with a large camera, three strobes plus all the usual dive gear. The photos speak for this cave - but the dive was long and hard work. Danny is an exacting master underwater when taking photos. Al and I had strobes on our backs plus a huge strobe which could be hand held to light other bits of cave. This used to go off in our eyes when at the back and it gave us both headaches. results are worth it though!

It is worth remembering that when you are doing a photo dive you are still doing a complex cave dive with stages, navigation and gas issues. It takes everyone being on the ball to make sure it is as safe as it is fun.

Day 3 we met with Fred and decided to go to Ponderosa. This was the place we did our first dive of our cave 1 course rather a long time ago so it was fun to go back. We had a bit more gear this time and a few more dives under our belts - but the excitement is still the same. Al loves the wide bedding plains here. I'm not so impressed by them but the dive was pleasant and it was good to see more of the cave.

Day 4 we went to Mayan Blue which is part of Sistema Naranjal. Our dive down B tunnel was complicated in the planning and got even more complicated in the execution when we again reached the end of navigable cave with gas still to burn. It was funny seeing Fred scratching his head as to where to go at a T that he was not expecting - turned out he hadn't got that far before.

He chose left and we ran out of cave after a few minutes. Thumbing the dive we returned to the T where we recalculated and headed off the other way. The cave soon headed up shallow again and markers switched direction - we were heading somewhere else quite unexpectedly. Examining a map we were well on the way to a traverse from B tunnel to A tunnel - via tunnels E and F.

We had a small incident on the way out. My primary reg started to free flow. First a little creep then, when I removed it from my mouth at the stage switch it really exploded. I shut the first post down, wound the second stage right back and very gingerly opened it up again. We were at the stage drop so no need to attraction the attention of the team - the bubbles and noise were enough to have them close by It held OK but was clearly not right - staring to creep again a few minutes later.

Al and Fred understood that the reg was open again but iffy so when we returned to the deco bottles I did a straight stage to stage switch rather than a return to back gas which I would normally chose to do to clear things away. Beyond this it didn't even make it into the post dive discussions which remained on the 'what a great dive' basis - so that was nice. The 1st stage turned out to be shagged so that went back in the box and we broke down one of our 6 stage regs to use for back gas the next day.

Day 5 was Chan Hol which is the furthest cave to the south that Zero Gravity dive, on the edge of Ox Bel Ha. We arrived at a patch of mud with a small puddle in the pouring rain with mosquitos coming out to munch. I was not best pleased with my 'holiday' at this point. Fred igeniously produced tarps and a brolly. Our first task was drysuits and after we were changed we prepped gear.

We kitted up and got into the tiny entrance pool, the line runs right to the surface which is needed as it's practically a zero vis restriction we had to pass to get in. Once through that the cave opens up and we see lots of dark cave but with limestone tunnels leading away and immediately a T.

As we head left we seem to swim through a heart shaped opening and into some crisp clear limestone. Vis is stunning and the cave goes through several different sections, we have narrow small passage which opens up into big cave. We pass through hugely decorated cave with thousands of formations, we move through lunar landscapes with craters of rimstone, popcorn style deposits cover the floor in some sections.

In places the cave reminds me of nohoch. We drop the stages quite early next to a jump - our plan involves using them to explore the jump later. Imagine being an explorer, how many small puddles (cenotes) do you jump in to hoping that you will find something. You wriggle into countless holes meeting dead ends. Then one day you are asked by a landowner to check out his puddle and you find a low restriction by a mud bank and head in. To find 1,000s and 1,000s of feet of beautiful white cave. Unseen for 1,000s of years.

For they have been seen before - in part at least. We came across human remains a long way back which have been dated to around 15,000 years ago. Mayan pots are still there which are around 500 years old, pristine and still lying as if they were left yesterday. Imagine being the water carrier, guided by burning torches thousands of feet in away for daylight. Imagine being injured, or dying there, or carrying the body of a loved on in to the cave away from scavengers. For we do not know how or why they were there.

The cave is still under survey by a small team but the lines appear to have been laid exceptionally well, with good skill on the part of the explorers and those who have surveyed since. It is so nice to dive a cave which still appears pristine, it help you feel as if you are seeing it as history made it appear.

Day 6 we met up with Chris and after a lot of discussion headed to Jailhouse which is a far extension to Mayan Blue. This was a complex navigation dive which we discussed carefully beforehand but would never have found ourselves. Multiple jumps and Ts, which were sometimes unmarked and hidden in cracks, had to be taken to reach our destination where we ended the dive based again on navigable cave.

Jailhouse has essentially two different parts - a fresh water layer of dark cave with lots of brown and green, then below the halocline there is the salt layer which is very white and blue. It's part of the Mayan Blue system and in the salt water layer you can see the resembalance. The dive was a never ending changing story. Green tannic water changing to white highly decorated cave. Small areas with fine formations branching into huge passages with halocline down the middle. Swim high in the room in wide dark cave, swim low in the room for bright white walls - bleached by the salt water. For those of you who fuss about ultra fine tuning your weighting in salt/fresh - learn a little. It's not that big a deal

We enter through the restricted opening which is silty with organic matter and as the cave opens out we almost immediately hit a T. We turn left and head off into some darker cave. After a short distance we jump off the line heading deeper passing through the halocline into some very white and blue cave. Lots of formations line the tunnel and we swim along in some tall passages. We reach the fire pits where the cave drops down to 45m and where there is lots of charcoal. Before the dive Chris had told us about seeing a 12,000 year old skeleton in this area which had since been excavated by the Mexican institute of archaeology. The passage continues but after 10 minutes the line ends. Chris pools out a spool and sets a jump up through a crack in the ceiling, we head up back into the darker cave. We head right before again reaching the end of the line and jumping now back onto the mainline. We are now swimming through very big sections of cave with the halocline mid passage. This creates quite a strange view with blue and white cave below green and brown and the mixing layer creates a very distorted view of one or the other dependent on where you are. We spread out across the passage which gives us lots of light.

Having travelled a distance Chris then sets the final jump and we descend down into a lower passage - this one is all low bedding plains and rimstone. We carry on to the end of the Line where we thumb the dive and begin exiting. On the way out we take put time particularly at the fire pits. After a little deco we surface to the cold weather. The cenote feels distinctly warmer than the air temperature and we chat in the water for some time

Another series of fantastic dives in Mexico. We did around 18 hours in water over the 6 days and saw some amazing sites. Sites which had we gone alone we would simply not have seen.

For those of you who cave dive in Florida or France, Mexico is very different. Lines are often well hidden, caves very complex and jumps unmarked and very easy to miss. When you have a destination which involves five or six jumps or Ts it is easy to spend more time searching for the route than on the dive itself - and thus you see less cave.

Add to this the fact that many sites are unmapped (publicly at least) ate subject to negotiation with the owner who speaks little or no english and may live away from the site necessitating a key pick up in back street Tulum, may be far into the on a road which is unmarked and where there is no indication as to where to park, where to enter the water or where the line is. You can dive Mexico without a guide - I have. But if vacation time is limited and you want to see the best that they offer - then a guide means you do. With Zero Gravity, the guys dive as members of the team (if you want instruction pay for it - don't book a guide and expect to be trained) and treat divers with respect and good humour.

I can't wait to go back.