Building your own Ship

Setting the NC parameters in a Sailboat
Setting the NC parameters in a Motorboat
Customizing the HUD
Adding engines and instruments
Adding sails.
Making your own mesh sails.

Using the resulting boats

Using the main navigation page of the HUD.
Instructions on how to control your boat.
Setting up your sailboat.
Hints on how to sail a boat.


I sell script kits for making motorboats and sailing ships. I'm trying to combine the documentation for the two togther so bear with me if I talk about features here that you don't need.

This document describes my kits that can be used to bring motor boats and sailing ships to life in Open Simulator. From the smallest dinghy to a tall sailing ship. The kit consists of a root prim (keel) with a script that implements motor and/or wind powered non-physical sailing. I'm shipping the sailing kit with a few prims attached now, one mast, sail and flag. Both kits have a "COM HUD" prim attached, this looks like a little whip antenna and its job is to communicate with the HUD. The boat script does its own physics calculations thus does not use the physics engine. The calculations are done infrequently and then the position is interpolated by llSetKeyframedMotion. The result is smooth motion without the overhead and non-deterministic behavior of SIM physics. The same script also works on many different grids. It will work despite ODE, BulletSim, PhysX, Havok or any other physics engine.

Getting Started:

The easiest way to build a boat is to take the keel just as you got it from me, and link it into your boat build. Link it in at approximately the desired waterline of the boat. Make sure it remains the root prim of the boat. OK you are done, you can drop your boat in the water and try it out now! Well, not completely done, the pilot position will probably be wrong, but you can fix that with the .prams NC described here. There are many other parameters in that NC that you will want to tinker with to make your boat behave just right. You will probably want to add sales, motors, instruments and other details to the boat, but you can do that incrimentally. Just link in another instrument or sail, change one parameter, and try the boat out again!

The boat build that you link the keel to can be a large build made out of prims. A non-physical boat does not have a limit on the total number of prims allowed. However, you should read the section below on tuning your boat to reduce lag on the servers.

The boat build that you link the keel to can be a single mesh prim. As long as the keel remains the root prim, it will work fine with prims, mesh or a combination.

It is not necessary to keep the keel in the keel shape. You can change it to a block prim and change its size to make it easier to hide it inside your build. You can even make it transparent. The boat rocks, heels and turns around the center of the keel prim, so the location of the keel prim matters. It must be on the centerline of the boat, and is usually pretty close to the center for-and-aft.

It is not necessary to use the keel prim at all. You can copy the script and the rest of the inventory of my keel into the root prim of your boat and it will work fine. (In fact some people prefer to do this to avoid having Kayaker Magic show up as the creator of the boat). If the center of your root prim is not at the waterline, you can correct for this in the .prams NC described here.

Tuning your boat for Low Lag on the Servers

When an object moves in-world, the Physics Engine must re-calculate the physics shape of the moving object. To keep this process from using up all the CPU power of your servers, you should keep the "physics shape" of your boat as simple as possible. The easiest way to do this is to mark your whole boat as a phantom object. This is not very satisfying, since you cannot walk on the decks while in dock. The next thing to try is to mark the root prim as non-phantom. Mark the deck as physics type "prim" for walking on it, and mark every other prim in the build as physics type "none". If the deck is part of a larger mesh build that has many parts on it, it is common to build a "physics shape" for the boat. This would be an invisible prim that has the deck and other important parts that must remain "solid" so the rest of the boat can be type "none". My catamaran, for example, has an invisible prim (made by changing the prim type of the keel to a block) that is underneith the hulls and trampolene. My Pirate Gunboat has a simple mesh hull that is invisible to fill this purpose. Then all the rest of the prims in your boat can be physics type "none" and they will not bog down the server as your boat moves. When you add new prims to your boat, like sails, instruments or outboard motors, check them and mark them as prim type "none".


The script will sail the SIM wind, wind broadcast by Wind Setter Buoys, or internal wind. The script does four kinds of sailing calculations: spinnaker, jib, fore-and-aft and square-rigged, separately or together. The the boat heels over in the wind, tacks and gybes realistically. A HUD has buttons to reef and furl the 4 types of sails separately. The forward/back keys on the keyboard set the sheets on the sails. (This means setting how far forward the sails are allowed to swing, sometimes called trimming the sails). You can configure these keys to control the jib sheets, the fore-and-aft sheets or both of them together. There is also a slider available for the HUD that can quickly set the sheets as well.


The left/right keys turn the boat and the page-up/page-down keys control the motor, if your boat has one. The HUD has a mode to allow only you or your fiends to pilot the boat. You can give copies of the HUD to your friends to pilot your boat. The HUD has modes to disallow, allow after asking you, or always allow others to connect their HUD to your boat. In Captain mode, the boat will give copies of the HUD to visitors. (Note: If you use this, put a copy of the HUD in the boat's inventory and mark it NO-TRANS). To return to the dock just jump off and the boat will teleport back to its starting point. (Disable this with the HUD if you wish). A “moor” button in the dialog will allow you to temporarily over-ride this so you can stop and get off the boat, then get back on and continue your journey. The boat starts out with just one prim and can only sit the pilot, but you can add as many prims and seats as you wish. A non-physical boat does not have the prim limits of a physical one.

Weapons and Damage

The script can take damage from Magic Bullet weapons, and also from SPD cannonballs in InWorldz. In the parameters NC you can set the total damage the boat can take and how fast it recovers. On each hit the boat drops a half a meter but rises back up if underway. If the “health” of the boat goes to zero it will explode and sink to the bottom. You can re-float the boat by “casting off” in the dialog, but this doesn't repair most of the damage and your boat will easily sink again. Only time or a trip back to the dock can fix it. Damage messages are passed on to the instruments and the sails. I have a new meter that graphically shows damage. My newest sails change textures to show damage. As the damage to your boat increases, the sails become less and less effective. All this can be disabled by setting takedamage=0 in the parameter NC of the ship.

Come try out demo boats!

To see several sailboats built from this kit, come to my Chandlery. To get links to all my stores, check out my blog. In my Chandlery stores you will also see many other instruments, engines and other things to add to your boat.

How to unpack your boat kit

Depending on where you bought it, the kit may come in a folder or a box. If it arrives in a box iyou must rez this and unpack it into a folder in inventory. When you buy my sailing ship kit from a marketplace or a vending machine, it will come in a folder named "Sailing Ship Kit" or "Motor Boat Kit". Inside this folder will be several prims: The keel, jib sail, wind flag, pennant, remote, an extra seat prim and a wind setter buoy. Also a copy of this document for reference. You have to add everything else to build the boat of your dreams!

The keel prim must remain the root prim at all times. You can hide it inside your larger build, or reshape it into a hull or other part. Even before you do that, it will float and move like a boat. It has animations to make your avatar stand and act like you are turning a ships wheel. When you turn on the “motor” the boat will move without the wind. It will not make any engine noise, for that you will need an “engine kit”. Ocean Engineering sells several engine kits that make different noises, have propellers, outboard motors, paddlewheels, thrust levers, etc. At my Chandlery (a nautical term for a Marine Supply Store) I also sell instruments: Compasses, speedometers, tachometers, wind meters and more. All these items will work well if linked into this boat. (For example, the tachometer will track the motor speed you set with the Page-Up key).

The boat in inventory may say NOMOD, but this is because of the scripts inside. The prims are MOD and you will be able to modify them to build the boat of your dreams. The boat kit is COPY so you will be able to make several different boats, and launch several copies of each. There is a TRANS version available that allows you to make boats for sale, contact Kayaker Magic for information about this.

The keel will be the axis that the boat turns and heels around. Because it is MOD you can change size, textures, shape, make the keel prim invisible if necessary, add all the detail prims you need, passenger seats with their own poses, etc. I like to change the keel into a boat hull sculpt to save on the total number of prims. It must remain the root prim, and the water offsets and rotations are all calculated relative to the keel position. In the keel here are three pilot animations. I ship the ship with a set of standing animations that makes you look like you are turning a wheel. If you like I have a set that makes the pilot sit and act like she is moving a tiller. Or you could replace these with your own three animations. There is a parameter NC in the keel that sets a bunch of things: the position of the pilot, the boat friction with water, the motor and sail acceleration (the difference between the acceleration and friction determines the maximum speed), etc... Some sails also have a parameter file for setting parameters that cannot be figured out from the main build.

Resale Version There is a resale version, but this is not sold in a vendor, you must IM me to get this version. The resale version will be TRANS so you can sell it to your customers. You will be nagged to remove TRANS before reselling to your customers. It is sold under a royalty system, the initial price of the kit is low, then you pay a royalty for each copy that you sell (or give away). If you buy the non-resale version then change your mind and wish to sell the boats you build, I can upgrade you to the resale version for the difference in price.

Help and Info Notecards (resale kit only)

The boat comes with two note-cards inside that it gives to people who click on it or ask for help. The help NC is given to the owner, and starts out with instructions on how to use the boat. The info NC is given to anyone else who clicks on the boat when it is private, or who asks to bring up the setup dialog when they are not allowed to. This note-card gives a general introduction to the boat kit with links to my store. You may wish to edit or replace these note-cards with ones that give details about your boat and have links to your store.

For Sale and DEMO Mode (resale kit only):

If you have the resale version of the boat builders kit, an extra sitting mode appears in the dialog called “FOR SALE”. When you put it in this mode the cursor will be a $. This won't work right until you have also set a price and marked the boat for sale in the general tab of the build dialog. If you change the boat back to FREE RIDE or CAPTAIN, then the boat will go into a demo mode. In demo mode, anyone left clicking on the boat will immediately be sat in the pilots seat and can sail the boat away. Since UNSIT.DOCK is the default, if they abandon the boat it should return to where it was when they sat on it. In this mode, if the boat is marked for sale in the build menu, someone can still right-click, select buy, and buy a copy of the boat.

You can put the boat in a vending machine or a boxed set. The first time it is rezzed, the script will detect a new owner, disable any builder/creator features and always come up in sit-on-click mode. The final owner of the boat can still put it in FREE RIDE or CAPTAIN mode to let their friends ride it. But it will never go back into buy-on-click mode and the system will not let them set the boat for sale.

Permissions (boat builders only):

The boat kit is MOD so you can edit it to build the boat of your dreams. The scripts are NOMOD, so this makes the boat look no mod in inventory sometimes, but this does not stop you from modifying all the prims. The boat kit is COPY so you can build many vehicles from one kit and launch many copies of each boat. The resale kit is also TRANS so you can build it into vehicles that you can sell to others. The TRANS version will nag you with ANNOYING RED TEXT to change the permissions and remove TRANS for the next owner. You have to take it back into inventory and rez it again to get the red text to disappear. I'm not doing this because I don't trust you! I am forever forgetting to set some of the permissions and originally put that code in my builds to remind me do do these things!