These strengths differ from rope to rope, but one thing that doesn't change: a tube rope is a lot stronger than a ski or wake rope. A couple examples are that a 2 person tube rope is a little over 2,000 pounds and this 4 person tube rope is over 4,000 pounds! That is a lot of weight to be transferring to the tower AND the hull of the boat!
A couple things we have noticed on some of the boats we have installed on is that even the ski eye on the back of the boat has a pull rating. Most are generally about 2,000 pounds. This area is to be used for all towables, including inflatables.
In some cases the you have a tower that is strong enough to pull inflatables. At this point the question becomes is the hull of you boat strong enough to take the excessive amount of force. If it is not you could see some spider cracking in the gel coat, hull or worse. Most manufacturers tell you not to pull a tube from the tower. There are so many factors in pulling a tube its hard to ensure you are not going to run into issues. I know its the boring thing to do but we recommend playing it safe and continue pulling inflatables from the back of the boat.
In some cases the you have a tower that is strong enough to pull inflatables. At this point the question becomes is the hull of you boat strong enough to take the excessive amount of force. If it is not you could see some spider cracking in the gel coat, hull or worse. Most manufacturers tell you not to pull a tube from the tower. There are so many factors in pulling a tube its hard to ensure you are not going to run into issues. I know its the boring thing to do but we recommend playing it safe and continue pulling inflatables from the back of the boat.