Pacemaker Boats

[merwin10]

This Post is for informational use - I thought it might come in handy for some of you – and to stimulate some discussion - Mike

On our smaller boats with limit mounting height distance is not going to be to far given the curvature formula - So why do you want radar for Collision Avoidance - One of the main specifications to close in detection is the vertical beamwidth - the more narrow the beamwidth the further out your Invisible Zone is - That is why you see many radars tilted forward about 5 degrees - How do you know what your Invisible Zone? That is easy - pick a buoy - head to it - notice that as it enters the top of the screen the dot representing the buoy is large and as you approach it gets smaller - that is due to the horizontal beamwidth - Now as you approach the buoy watch the screen the dot representing the buoy will disappear on the screen and reappear behind you - The distance that the buoy disappeared on the screen is your Invisible Zone - In other words if there is another vessel that is within that distance in the fog you won't see it on the radar -

Also there are other factors that effect your Invisible Zone - First is height - the higher the antenna the further the Invisible Zone - Speed effects the Invisible Zone also - when your boat is on plane the angle of the antenna is raised increasing the Invisible Zone distance - There are several other specifications that effect this also one being pulse length (PL) and Pulse Repetition Rate (PPR) to understand how these specifications effect the Invisible Zone you must understand how radar works - So just to give you the basics the shorter the Pulse Length and the fast the Repetition rate the better you are going to see targets close to you!

So to put it in a nut shell Collision Avoidance is the main use for radar on our boats and as everything on a boat radar is a compromise - The higher the radar the further you can see - a the cost of increasing your Invisible Zone -
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"Best part of Boating -- is the people you meet"