I prefer to jack up the trailer using the frame/not the axle.

At home, I use a cinder block, then place a scissor jack on top of the cinder block and jack up the trailer.

I've looked at floor jacks and bottle jacks and don't think either are tall enough to jack up the trailer using the frame.

Don't really want to carry around cinder blocks in my vehicle.

Any good solutions?

Jack it up by the axle. You can get a small floor jack that will roll right under. I have one that has a case. Slides right under back seat and stays there. I can't name the times I've stopped and helped someone jack up there trailer using this little floor jack.

NEVER use a cinder block. They are known for crumbling at the wrong time.

OK, thanks.
I've always been concerned about using the axle, but I guess it does support the weight of the trailer and boat and then some all the time.

If you raise with the axle, make sure you put the jack close to the spring, to make sure you don't bend the axle. Some are thin tubing. IslandJim

+1, I carry a wooden block. I have gotten in the habit of just carrying my small floor jack. I rarely have back seat passengers so it just stays on the floor in the back of my truck. When I had a single axle trailer I normally put the floor jack under the spring hangar from the back side. With my dual axle I can put the floor jack between the tires and use the middle spring hangar.

Thanks
I was thinking about getting a wood block or two.