Boat covers are necessary, but you need to take care of them, provide support for them and check them regularly as water can pool on top creating a potential disaster.
Having a proper support under your boat covers is the only way you can prevent it from collecting water on top. The question is what type of support and how to get one, plus the problems that go with having a support.
Even with snug fitting and tight boat covers, once it starts raining, they can start to get heavy and sag a bit, forming a low point. This low point then fills with water and causes them to sag more until a large amount of water is present.
If your boat is on the hard water filled boat covers can get so heavy, they can cause substantial damage inside the boat.
The best solution is to have the professionals to handle the problem
Boat covers support kits and systems can be supplied by the company who supply your boat covers. These covers are constructed using long lasting materials and designed to support your boat covers for many years. They have the advantage that they are collapsible and easily stowed with your boat covers and then easily erected when you want to put your covers on.
DIY boat cover supports
Making your own supports to hold up your boat covers is a cheaper method, if you have the tine and ability.
Heavy walled PVC tubing is a great option as many good designs can be created using t junctions and elbows to make a good supporting system
If you are good carpenter you can knock up a wooden frame, the biggest problem is erecting or removing it and where to store it when it’s not on the boat
Flying bridge, shade tops and ski poles
If you have a permanent structure such as a ski pole, or shade top half the work is already done and you may be able to rig some lines and poles to keep your boat covers supported in any weather or use a system to suspend the boat covers on lines.
Pole and strap kits
For smaller boats you can get or make your own pole and strap kit, these are usually the least reliable and need to be checked regularly as they can bend with wind and a buildup of water
Bow and socket kits
These can be made to fit your particular boat with sockets placed at strategic places to prevent sags and provide support to stop low spots
Take a walk around a busy marina and look at the boats moored or parked there, often with absentee owners. It will not take long to understand the importance of providing good support under your boat covers to stop water collecting and pooling their.