It was a mistake most of us make sooner or later. I put the boat in reverse to maneuver into an anchorage, but immediately stopped when the engine made a sound I didn't recognize. A quick inspection showed the tow rope for the tender was caught in the propeller.

Thankfully, we SCUBA dive.

In the two years we have been cruising aboard Sea Foam, our 40-foot TransPac Eagle trawler, diving has added many new dimensions to our experience. It allows us to explore in unique ways, commune with rare and amazing creatures, do some work on the boat and, occasionally, it gets us out of a jam.

My husband, Rick, put on his gear, went under and freed the line without any damage, putting a quick end to what could have been a costly or time-consuming problem.

When I met Rick five years ago he was not only looking for a wife who loved the ocean and was willing to live aboard a boat, he wanted a dive partner too. Rick is a certified dive master with 30 years of experience in the sport. I grew up with a swimming pool in my backyard and always loved being underwater, so it did not take much convincing for me to give it a try.

Rick asked me if I was claustrophobic or afraid of dark basements, but I think the number one question to determine if you will like diving or not is more simple: are you comfortable and confident in water?

A woman who attended my SCUBA certification class brought her reluctant husband to the lessons. She was very excited about diving, and not at all apprehensive. But she ended up unable to complete the requirements. She could not get more than 15 feet under the water without feeling a sense of panic. Her poor husband is now certified, loves diving and cannot go all that often.

It is important to be comfortable in the water and in reasonably good shape. You don't have to be able to swim the English Channel, but you do have to be able to move around in the water. In truth, experienced divers actually try not to swim very much, in order to conserve air (the more you exert yourself, the more air you breathe). During the certification course, you will need to swim 200-yards without stopping, though there is no time limit, and tread or float for 10 minutes.

Honestly, the most difficult part of diving for me is getting all the gear on in a boat. The weight belt is heavy around your waist and a tank on your back makes it difficult to bend and pull on fins while maintaining balance. In my opinion, strength and flexibility are called into play more than a great frog kick or breast stroke.

GET CERTIFIED

The first step to getting yourself underwater is to take a certification course from one of the sport's top organizations, the Professional Association of Diving Instructors (PADI) or the National Association of Underwater Instructors (NAUI). PADI has the world's largest recreational diving membership. The organization's dive centers, resorts, educational facilities, instructors and dive masters teach the majority of the world's recreational divers.

PADI offers short courses for those who want to try diving on vacation. The courses don't provide certification, but they do get you in the water at depths from 20 to 40 feet. Certification requires PADI's Open Water course, which takes 20 hours and is generally completed in three parts. There is a classroom portion that takes four evenings; a weekend of training with the gear in a swimming pool; and a weekend packed with four training dives – called "check out" dives – done with an instructor in the ocean, usually from shore.

The course is "performance based," which means that you earn your certification when you demonstrate that you have mastered the required skills and knowledge. Some people learn faster than others, so how long it takes can vary. The course will set you back about $400, but completion means you are trained to dive without supervision to a maximum depth of 60 feet. The certification is valid for life and recognized worldwide.

Thereafter, you learn through experience. I keep a log of my dives – 71 so far – that lists the location, depth, visibility, current, geography and the life I saw while under. I also copy a chart image of where we were, to help us locate the same spot or to better position ourselves next time. Finally, I rate the dive on a scale of one to 10.

For more advanced diving, it is best to learn with an instructor. Deep dives, night dives, "drift dives" and dive sites with moderate currents are challenging, and doing them without proper training can be dangerous. Advanced courses teach a variety of skills, from improving underwater navigation to basic rescue techniques. Rick says these courses are like collecting Boy Scout badges. You gain more experience and confidence with each dive and you get the benefit of learning from trained people.

It is important to choose an instructor whom you trust. They should be thorough, patient, and supportive. Talk to them in advance and observe a class if you can. Do not stick with someone you are not comfortable with, and don't be afraid to ask for references from previous students.

"˜NARCED OUT'

Scuba diving is a dangerous sport. Dive too deep and you risk Narcosis, a state similar to intoxication that can impair judgment and coordination. A "narced out" diver can make fatal mistakes. Rise too quickly from a deep dive and you may suffer Decompression Sickness, sometimes called "the bends." An explanation of either problem makes it easy to see why you need proper training to be successful and safe.

Let's take Decompression Sickness. At sea level, the atmosphere exerts a pressure of one atmosphere, but that increases by another one atmosphere with every 33 feet of water. If a diver ascends too rapidly to the surface, the nitrogen that was dissolved in their body under pressure at depth might form gas bubbles, which can be painful or even life threatening in extreme conditions. (People with decompression sickness tend to bend over, hence the name.) Of course, you can avoid this by paying attention to dive tables that explain how to properly decompress as you rise. But you have to know what you are doing, and proper instruction is the key.

The nice thing about taking a class with a friend or your spouse is you will have someone to go diving with you once you complete your course. My dive buddy is also my husband and I would not be comfortable to dive with anyone else. I know I am safe with him and that he is always going to look out for me underwater.

Having said that, I took my Open Water course without Rick in the vicinity. That was probably a good idea, because he would explain things differently than the dive instructor, which may have been confusing. When I started diving with Rick, he said he was impressed with the information and techniques the instructor had shown me.

BUYING GEAR

No doubt, you have heard that diving is expensive, and it certainly can be. But my experience is that diving is what you make it. Boating is expensive too, if you insist on having the best of everything and buy it all at once. Much of the cost associated with diving is often flying to a location, staying in a hotel, chartering a dive boat and renting gear. Those who own a boat dodge many of these costs.

The way I see it, diving gear falls into two categories: required items and gadgetry. Required gear includes a mask, snorkel, fins, buoyancy compensator, regulator, dive computer or watch, weights, and a wetsuit or a drysuit, depending on location and conditions.

Gadget gear is usually associated with a particular type of diving – night diving, underwater photography, or search and recovery – and includes knives, underwater slates, cameras, strobes, video recorders, lights, lift bags, lines, reels and even underwater laser pointers.

Ask any 10 divers what to buy and what it should cost and you'll get 10 different answers, many of them passionate. There are also any number of books, magazines and web sites dedicated to the topic. While it may be unwise to wade into these waters, I will try to give you a brief survey of essential gear and what it can cost.

The basics start with a mask, which can run from $20 to $150, and choosing the right one is important. Make sure the fit is perfect because water in your mask can ruin a dive. Snorkels range from $17 to $150 and fins vary from $30 to $450. A dive light is also essential. A bright full spectrum underwater light will cost at least $300.

A regulator, the mouthpiece unit that attaches to a diver's tank, usually includes a primary mouthpiece, an alternate mouthpiece (called an "octopus"), a pressure gauge to measure the amount of air in the tank, and a depth gauge. They run from $500 to $1,000.

A "buoyancy compensator" or "BC" is a sleeveless jacket that secures a tank to the diver's back. It can also be inflated or deflated to allow divers to become neutrally buoyant. Typically, buoyancy compensators run from $400 to $800. Weights are about $1.70 a pound.

Tanks range from $200 to $400 and are made of aluminum or steel. The most common setup for recreational use is a single aluminum tank that holds 80 cubic feet of compressed air. Tanks also come in larger and smaller sizes, and some dives like commercial or extreme diving, require several.

Dive computers are electronic versions of diving tables that help calculate depths and times. Worn underwater, they vary in function and complexity, from simple units for beginners to the full-scale rigs used by pros. A basic computer will cost from $300 to $1,000.

Exposure Suits vary according to type – wetsuit versus drysuit – and range in price as well. My first summer diving I was in a $250 wet suit, which allows water between your skin and the suit. It heats up from body temperature and helps insolate the diver. However, we were diving in 48-degree water, so it got pretty cold after about 30 minutes. The cold affects your ability to think and your physical response time slows, which can lead to an accident.

The following summer, we bought drysuits for about $1,500 each which do not allow water to touch your skin. We wear fleecies under the suit, which is completely enclosed. Only your head and hands are exposed, requiring a hood and gloves to complete the suit. Now, diving is like going underwater wrapped in a sleeping bag. We are able to stay under for longer periods without feeling cold, and our fleecies are dry when we take our suits off, so long as we have taken care to tuck the seals around our necks or wrists properly.

OUR EQUIPMENT

In most places you will want to dive, you can usually find a dive shop near-at-hand to rent tanks and other gear. Because we dive in remote areas, where dive shops are rare, we purchased all our equipment. We estimate that our gear has cost us about $4,000 each, but that includes upgrades over time. Those looking to save money can find used equipment available that has hardly been touched. Many people get into diving, buy all the gear, then drift away from the sport.

We store our equipment in a dedicated dock box on our upper bridge. Rick hauls it down and we check that all the instruments are working properly. This includes our gauges, regulator, dive computer, tanks – everything. If there is a problem, it is better to discover it and fix it onboard before loading our gear into the tender. But we do carry a box of spare parts with us, just in case.

We also own an electric breathing-air compressor manufactured by Jordair, with a Bauer pump. It fills up our tanks with compressed fresh air. The machine weights approximately 50 pounds and is about as big as four scuba tanks strapped together.

Our first dive compressor was located on the stern deck, though we stored it in the lazarette between trips. We always felt bad filling our tanks because the gas motor sounds just like a loud lawn mower. In a peaceful, quiet anchorage we had a few dirty looks when we turned on our compressor for 30 minutes each day. But only once did a fellow boater make a comment to us and move to another area.

Sometimes bad things happen for good reasons. Last summer our fresh air intake hose, which normally hangs over the boat, found itself in the drink and sucked salt water into the compressor before we noticed it. We had a toasted compressor after only one dive.

The result is that we now own a better, quieter unit that is stored under the stern cockpit in the lazarette and draws its power from our generator, reducing the amount of gas we need to carry onboard.

THE TENDER

We needed a boat that was large, stable and powerful to allow us to dive in remote areas, and so we had Catch-Up built. The boat is a bright red, 12.5-foot Polaris RIB (rigid inflatable boat) with a four–stroke, 50 hp Mercury outboard attached. The engine has an electric tilt, which is very useful for motoring in shallow water.

We often get comments on the size of our engine, but we feel it is necessary. The boat goes 26 knots, and it is not overpowered when loaded with the two of us and our gear. It allows us to navigate through all types of water conditions, including tidal rapid areas.

We have equipped Catch-Up with an Icom VHF radio, a Garmin portable GPS/Chart Plotter and depth sounder, a collapsible anchor with 100 feet of line, and a bilge pump. For diving purposes, we had Polaris install extra handles to assist getting in and out of the water and to tie off equipment. We also had extra rubber pads installed for wear protection when hauling in SCUBA equipment and traps for prawning and crabbing.

Before we pull away from the Sea Foam to the dive spot, we check that we have everything in the boat. More than once we have arrived at the dive spot only to find that we forgot our fins or our weight belts. The time it takes to get back to the boat and grab the missing equipment means the difference between a safe dive and potential problems. It is never a good idea to rush a dive.

DIVERS DOWN

When I first started diving, Rick made sure to take me to locations that were easy. Current was not a factor. But as my confidence improved, so did our dive locations. With time and more experience, he started to expose me to more challenging sites.

We've seen some amazing things. Once when we had just surfaced after diving near Stubbs Island in Queen Charlotte Strait, Rick and I heard the familiar sound of a whale spouting. With water still dripping from my hair and suit, I turned around in the tender and there was a small pod of whales swimming right past where I had just been diving. Lucky for us, they were resident whales that only eat plankton. Still, it was an amazing sensation seeing them so close to where we had just been. I wonder what it would have been like to have seen them while under. Yikes!

The more an area is swept by current, the more life there is in that location (though if there is too much current, sea creatures too can get swept away). In these types of areas, the switch between ebb and flood can be only a matter of minutes, so timing is everything.

Once Sea Foam is anchored in an area we want to explore, we start looking at our electronic charts for places that might make good diving grounds. We look for areas with vertical reef walls, usually marked by tight depth contours on the chart, in areas where current is present. Here, nutrient-rich water brought in on the ocean currents attracts schools of fish, plant life and all manner of sea creatures that feed on the plankton.

We have to study the timing and direction of the water flow so we can dive at the correct time, without being overpowered by the current when we resurface. Once we have determined an area that looks like a good dive spot, we go out in our inflatable with our portable sounder and study the "lay of the land" on the screen.

We also look at the current flow at slack tide. For divers, the absence of a current means less effort is required to remain at a given site, and there is less likelihood of drifting away from the boat. Slack water can also provide better visibility, because there is no current to stir up sand and silt from the bottom. Except when "drift diving," which takes advantage of currents, it is standard practice for divers to dive at slack water.

Like navigational charts, sometimes the current tables do not match the conditions we observe, and we pay careful attention to what is actually happening in the water. A single knot of current doesn't mean much on the big boat, but one knot of current in the water can make a big difference when trying to get back to your tender without a struggle. Swimming at the surface with scuba gear on is not as easy as swimming in a bathing suit!

We try to arrive at the dive spot 30 minutes before we should be in the water. This gives us plenty of time to get our gear on and position the boat. We motor to the dive location, and tie our bow line to a long rope with a grapple hook attached to the end. I clamber to shore and hook the grapple into a rock crevice or wind it around a rock. Once back in the boat, we back away from the rocks and throw our anchor over the stern. Now our inflatable is secured in two places, and away from the rocks.

While we get our equipment on, we watch the water and determine the direction we will go. Before we splash, Rick gets his bearings using his compass. We typically go down the anchor line, clearing our ears as we go, and meet at the anchor to check in with each other. We make sure the anchor is secure, give the "everything's okay" sign and off we go. I swim behind Rick because I want to know where he is at all times. Even with 71 dives in my log book, I am still tentative and always close to my buddy.

When we first get in, we head off in the direction of the diminishing current, descending between 60 and 90 feet. Once we feel the water slack, we head back in the other direction and slowly ascend, gauging the current flow as we go along. As we travel upwards, we are passing new sites and seeing different life at the different depths.

HEADING HOME

Rick is watching his compass all the while to have us surface with the boat in front of us, not behind us. If we were to miss the boat and go beyond it, we would likely have to get to shore, take off our gear and walk to where the boat is tied up. In all our dives, we have not once come up past the boat.

I did almost miss the boat once, because I wasn't paying attention. I was laying on my back after we had surfaced, relaxing, marveling at the experience and was not watching where I was going. Rick hollered to me to get to the boat, but by the time I looked around it was abeam of me and the current was pushing me past it. I had to paddle hard and fast, but I managed to grab hold of the bow line and held on until I caught my breath. It would not have been a total disaster, because I would have drifted along to shore. Rick would have gotten into the boat and picked me up. But it did teach me a lesson: just as in cruising, there is no room for complacency.

Which brings me to that work on the boat that I mentioned. Often after returning home from a successful dive, Rick will go under the boat and inspect how things are doing. He will check the zinc plates, look for dings in the propeller, make sure it turns freely, look at the cutlass bearing, check the condition of the bottom paint and whether or not there is barnacle build up. He also checks that all the water intakes are clear. When you consider that it costs roughly $300 to haul the Sea Foam out of the water, these inspections help save money. They may even offset the cost of some of that diving equipment.

Carol-Ann Giroday and Rick LeBlanc live aboard Sea Foam, a 40-foot Eagle Pilothouse trawler based on the Fraser River in Canada. Carol-Ann is a teacher and Rick is an engineer. Their work has appeared in magazines such as Sea, PassageMaker and Power Cruising.