we need some real numbers here. I will see if i can find them and post. But, keep in mind that the power dissipates at the square of the distance away from the emitter and is rapidly absorbed by solid materials like deck roof etc. My guess is you would not want to be in line with and close to the antenna when its operating
1. 4kW, was an actual number 4000 watts which is the rated power of both the Garmin GMR 18xHD High Definition RADAR and the Raymarine RD418D to list just two for RADARS rated at a 36 NM range and where the ones I used to come up with the 4kW number, sorry for not providing more data.
2. The eyes are only one of many soft tissues in the body in fact the body is mostly soft tissue, RF energy exposure is proven to cause temporary sterility in males; it kills sperm. In addition it can interfere with the operation of a pacemaker.
3. Deck roof protection? a Metal roof would reflect the energy and provide the best protections, a fibre glass roof would pass a majority of it, it is why they use fiber glass for whip antennas and RADAR radomes, wood would adsorb some but pass a great deal too.
4. Long term effects of repeated exposure to non-ionizing (i.e. electromagnetic, or RF) radiation is unknown. The Advice from Raymarine, was this from an information booth at a boat show or the telephone operator on the tech support, or was it from the guys that actually built designed and repair it? The first too are nothing more than SALESMEN and Script readers, the last too should know better, personally I respect my nutts to much to do such a thing, but hey if you want to be temporarily sterile, go for it, but for me I'll keep it as high as possible.
5. That being said, and having worked on High power RF devices for most of my adult life, I am 50, I personally would want the RADAR as high as possible, one increases line of sight there by increasing the ability of the RADAR to pick up targets, two increases the distance from me of the transmitting antenna and increasing the safety factor for me, by decreasing the amount of energy I could potentially be exposed to. Also note that everyone in our shop had to be tested annually, or any time there was an accidental release, this annual exam was a basic physical including eyesight and for the males a fertility test, as I stated earlier it can cause sterility. Females where assigned other duties outside the shop if they where pregnant, to protect them and the fetus. An interesting side note on the sterility issue, different sperm die at different exposure levels, the first to go are the Y chromosome male sperm the X sperm require a higher exposure to die off, if a guy in the shop said his wife or girlfriend was pregnant we would get a pink gift for him and his significant other, we where right more times than not, while I do not have specific numbers I would be willing to say at least 90% of the time. Of personal note, while I was in the shop we had my daughter, my son was conceived and born later when I was not in the shop but teaching the system, as we did not operate it that often in the school, only during specific lab days, at most 5 weeks out of the year, and not every day for for 8 to 12 hours, in fact the majority of people assigned to the shop who had children had their son around 6 months after they left the shop and stopped the routine exposure.
6. I agree with your statement "would not want to be in line with and close to the antenna when operating."