Radar - Mast or Post?

NbyNW · #1 08-08-2004

I am planning on installing a 2kw raymarine radar dome on a 36 ft boat with a 15.5 meter mast. Brochure says it can me mounted either mast or on a dedicated post. What are the advantages, disadvantages of each?

Jeff_H · #2 08-09-2004

Each location has its own advantages and liabilities. Mounting a Radar antenna on the mast gets it up higher. As a result mounting on the mast has the advantage of greater clarity at the ends of the range of the unit, sometimes a greater range, and usually less surface disturbance bounce back. The disadvantage of a mast mount is that it makes tacking the jib and genoa much harder (especially in lighter winds) and it can cause an increase in roll angle, a serious problem on many older designs.

Mounting on a post gets the unit clear of the sails and the interference of the mast but is lower and so gets more ground effects false readings. On a small boat or a boat with long ends post mounting adds significant weight in the ends of the boat increasing pitching and drag. It can be difficult to get proper support for the radar mast on many 35 footers. It adds one more thing to clutter up the afterdeck which can be a pain in the butt in handling the dinghy for example.

Jeff

NbyNW · #3 08-09-2004

Thanks Jeff. My boat is a full keel and fairly heavy displacement (7000 kg) so I think may be OK on the mast.
You are right about space at deck level being at a premium.

sailingfool · #4 08-09-2004

We have ours on a 12 foot stern mount mast which has worked well. If I were starting from scratch I''d try one of the mounts that fit on the backstay. The problem with the front of the mast is weight aloft, windage, and wear on the genny and unit.

Good luck,