What is a bluewater sailboat?

15th November 2021 Elena Manighetti

What is a bluewater sailboat?

A bluewater sailboat is designed to tackle long open sea cruising, such as an ocean crossing. The vessel is solidly-built and seaworthy, which means it can withstand any weather conditions. A bluewater cruiser is self-sufficient, so you can sail offshore for an extended period of time.

Let’s look at the characteristics of bluewater sailboats in detail. This article will hopefully help you understand why you need one, if you plan to sail offshore.

Just so you know, in this first part of the blog post, we will be talking about monohulls. We address bluewater catamarans and trimarans further down.

Construction

The material used to build the boat is the most important characteristic to look out for. A bluewater boat needs to be solidly-built, so it can withstand large waves and a collision with a floating object. The most reliable hulls are usually made of steel, thick fiberglass, or carbon.

Keel 

The underwater profile of the vessel is equally important. When you’re out in the middle of the ocean, you can’t risk losing your keel and capsizing. A bluewater boat typically features an encapsulated keel, as it has no chance of falling off. It will likely stay attached, sustaining some damage, in a crash. On the other hand, a bolt-on keel could be ripped off.

Rudder 

Rudders come in various shapes and are attached to the hull in different ways. Most bluewater boats feature a skeg-hung rudder or a rudder attached to the back of the keel. These types of rudders are protected in case of impact with an object, which means you likely won’t lose steering. Repairing your rudder in open sea is extremely difficult and if you aren’t able to steer, you’ll have to alert the emergency services.

Cockpit

A sea-going cockpit is smaller, so if waves wash in, it doesn’t take in much water. It features plenty of drains, so the water can drain quickly. Around it, there are solid clip-in points

Cabin 

Living offshore means having to sleep, wash, cook, and go to the bathroom underway. A bluewater vessel will have enough handholds around the cabins to allow the crew to move around the boat in heavy conditions. Falling when a big wave hits could mean breaking an arm or leg. A lower cabin will also create less windage, allowing the boat to be less affected by the wind.

Self-steering

A bluewater boat has self-steering on board. Even a big crew gets tired of steering by hand 24/7. Having self-steering allows the crew to rest, which is very useful if someone is hurt or sick. A serious bluewater vessel will have at least two methods of self-steering on board. An autopilot plus a windvane are a great combination because the windvane uses no electricity and is easier to repair.

Ability to heave-to

Heaving-to involves stopping the boat semi-still by pointing the bow into the wind and fixing the helm and sails positions. This is an essential storm tactic that allows the crew to seek shelter inside the vessel during heavy weather. It’s like parking the boat without anchoring. A bluewater boat will be able to heave-to.

Self-sufficiency

As we saw above, a bluewater boat is capable of being in open sea, independetly, for weeks or more. On board, there will be the right gear to satisfy the crew’s needs. For example, it will feature a power system, independent from the engine, that can generate enough energy to keep the instruments on day and night.

Typically, on an offshore passage, a boat will need:

  • Food storage

  • Water storage (5L/1gal per person a day) or a water maker

  • Communication gear (VHF, sat phone, SSB radio)

  • Fuel storage (240L/60gal)

  • An independent power system 

  • A fridge-freezer

  • Safety gear that complies with your country’s regulations

  • A storm drogue or sea anchor

  • Two or more reliable anchors.

Secondary factors - size, speed, comfort, and rig

While size isn’t a determining factor, it’s an important consideration. Being in the middle of the ocean, day after day, can be tiring. If you plan to go on long open sea voyages, you will probably want to go at a certain speed and have a number of comforts. 

The waterline is a good indicator of how fast a boat can go. Going at a 7-knot average, rather than a 5-knot average, can reduce your passage time by days. Plus, a bigger boat will have larger berths, more cabins, and more space to mount solar panels and wind turbines.

Comfort doesn’t mean just having more spots to chill out on, though. The way the boat moves changes a lot based on the displacement of the vessel and the shape of the hull. 

Usually, a heavy, long keel boat moves more gently than a lightweight fin keel one. However, an older, heavy, long keel boat will be slower than a modern racing yacht. You’ll need to find the right compromise for your needs and budget, based on how important each factor is to you. 

The type of rig and sail plan of a boat doesn’t necessarily determine how seaworthy the boat is. However, the crew will need to be able to handle the sails in any conditions. A bluewater sailor will choose a rig and sail plan that is suitable to the crew. For example, a cutter rig with a modest mainsail, a small staysail, and a yankee would suit a small, less experienced crew. A sloop with a very big mainsail and genoa would allow a strong, experienced crew to sail fast.

Bluewater catamarans and trimarans

What if you wanted to invest in a multihull to go offshore? In the past, only monohulls used to be considered fit for bluewater cruising. Today, however, there are a number of vessels that are deemed solid enough for ocean crossings. 

Bluewater multihulls are generally bigger and more solidly built. They feature either steel, carbon fiber, or thick fiberglass hulls. 

The sail plan is easy to handle for the crew. The helm is well-protected from the elements and is not located on a flybridge, where you are at risk of falling overboard. There are lots of handlebars and clip-in points around the deck and down below.


As you can see, if you plan to tackle an ocean crossing or go on offshore passages, there are plenty of good reasons why you should choose a bluewater sailboat. They are better built and equipped for these types of voyages, making your experience safer and more comfortable.

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