They work quite well but perform best if the marine antenna is mast mounted at the top of the spar. On a small boat the antenna can create a feedback issue if not installed far enough away from the phone end antenna.. They also simply like the added height... Ours works very well..You can never use 'inexpensive' and 'satellite' in the same sentence. Not a good option for coastal cruising unless your have serios money to burn for equipment, subscriptions, and airtime.
If the reception is marginal, you should look at cell range extenders; external mast mounted antennas with a booster. Wilson makes decent ones.
http://www.wilsonelectronics.com/store/index/category/37/mobile-solutions
This is so very true. We had complaints about poor cell service at the local hospital here. The cell tower is right next door and generally covers this medium sized hospital fairly well. We found some interference in the area and traced it to an 18 wheeler truck parked at a nearby truck stop. We could show, based on system performance, when the truck was there and when it wasn't. Improperly installed Bi-directional amplifiers, even the one's that claim to have feedback prevention circuits, must be installed properly. It can cause problems for everyone on the network in the area.They work quite well but perform best if the marine antenna is mast mounted at the top of the spar. On a small boat the antenna can create a feedback issue if not installed far enough away from the phone end antenna.. They also simply like the added height... Ours works very well..