Bimini top effect on MPH

[WildCatFan54]

So yesterday was by FAR the best weekend weather day this spring in Kentucky. It was also the first one that neither my wife or I were involved with other activities. I had been to the lake a couple times already this spring to do maintenance on the boat. I had already taken it out for short cruises after installing my lateral thrusters and reinstalling the TV XVs. So we headed to the lake together yesterday morning. My Bimini was still in the stored position , in the boot and securely strapped to the tower (the way I prefer it most of the time). We loaded up and headed out to our favorite spot . A secluded little cove about 2 miles up the lake from our marina. I had both engines running about 5100 rpms. Very little wind and cruising along about 25-26 mph as momma is not real fond of high speeds !! Boat was easily on plane and the sound of those synced engines was beautiful. So we spend most of the afternoon swimming , soaking up the sun , and just enjoying the heck out of the swim deck. I am then requested to put up the Bimini because momma is starting to get too much sun. No problem. I do as I'm told. Time comes to head back to port so I pull anchor , put away the ladder and here we go. I set both engines to 5100 rpms and surprised to learn the boat is struggling to even get on plane. We settle in at about 18 mph and bow is much more nose up than the trip out ? Still no wind and almost identical conditions as earlier. Can the Bimini alone have this big an effect on cruise performance ? I hope thats all there is as I even stopped once about half way back to check the clean out ports ? No problem there. I find the Bimini a major PITA to store after each outing for such a short trip but may have to start doing just that ?

 

[spatty99]

The bimini should have a minimal effect. I would guess almost nothing when accelerating to plane, and only 1 or 2 mph off top speed. Maybe you got something in the impellers?

 

[Bill D]

The Bimini shouldn’t have that much of an effect. It will have some, but not enough to make the boat struggle to plane. Did you notice any water in the bilge? These boats are notorious for leaks from the factory and a few hundred pounds of water could certainly have the described effect on performance.

 

[WildCatFan54]

Thanks guys ! Definitely no water in the bilge or any other storage areas as I'm OCD about checking that even during an otherwise leisurely day on the lake. So for as something in the impeller , that was my first thought and the reason I stopped. I didn't feel anything on either shaft but as you know can only feel the front side of impeller blades. I would have also expected a drop in one engine rpm if something went wrong there ? The RPMs remained consistent. Just a drop in mph.

 

[McMark]

Get it up on plane then pull the throttles back to 5100.

 

[haknslash]

The bimini on my boat doesn't affect top speed unless it's blowing really gusty winds that day. I've done enough top speed runs testing on my boat and the biggest influence has always been the current I'm running against or with more than the bimini being deployed or not.

You can't just set the rpm at 5100 and expect that to land in the same mph every single time. Lots of variables like wind, current, people moved to a different spot on the boat, gear, etc.

18 mph is not quite on plane, at least not in my boat as the bow will still be up plowing a little. Gonna need to be cruising in the low to mid 20's. Sweet spot for cruising on plane is 25-30 MPH.